[flutter_local_notifications] update cavaets and release build configuration sections in readme (#660)

* update cavaets and release build configuration section in readme

* fix  Scheduled Android notifications heading size

* fix wording

* another wording tweak

Author: MaikuB

flutter_local_notifications/CHANGELOG.md

@@ -1,3 +1,9 @@
+# [1.4.4+1]
+
+* Added details that platform-specific implementations can be obtained to the _Caveats and limitations_ section
+* Added a note on restrictions imposed by the OS by Android OEMs that may be prevent scheduled notifications appearing
+* _Release configurations_ section of the readme renamed to _Release build configuration_
+
 # [1.4.4]
 
 * [iOS] Fixes to ensure that the native completion handlers were called appropriately. If you had some issues using this plugin combined with push notifications (e.g. via `firebase_messaging`) when the app was in the foreground then I would recommend updating to this version. Thanks to [Paweł Szot](https://github.com/szotp) for picking up the gap in the code in handling the native `willPresentNotification` call

flutter_local_notifications/README.md

@@ -43,14 +43,15 @@ A cross platform plugin for displaying local notifications.
 * [iOS] Request notification permissions and customise the permissions being requested around displaying notifications
 * [iOS] Display notifications with attachments
 
-
-
 ## ⚠ Caveats and limitations
-Note that this plugin aims to provide abstractions for all platforms as opposed to having methods that only work on specific platforms. Each method allows passing in "platform-specifics" that contains data that is specific for customising notifications on each platform. This approach means that some scenarios may not be covered by the plugin. Feel free to fork or maintain your code for showing notifications in these situations.
+The cross-platform facing API exposed by the `FlutterLocalNotificationsPlugin` class doesn't expose platform-specific methods as its goal is to provide an abstraction for all platforms. As such, platform-specific configuration is passed in as data. There are platform-specific implementations of the plugin that can be obtained by calling the [`resolvePlatformSpecificImplementation`](https://pub.dev/documentation/flutter_local_notifications/latest/flutter_local_notifications/FlutterLocalNotificationsPlugin/resolvePlatformSpecificImplementation.html). An example of using this is provided in the section on requesting permissions on iOS. In spite of this, there may still be gaps that don't cover your use case and don't make sense to add as they don't fit with the plugin's architecture or goals. Developers can fork or maintain their own code for showing notifications in these situations.
 
 ##### Compatibility with firebase_messaging
 Previously, there were issues that prevented this plugin working properly with the `firebase_messaging` plugin. This meant that callbacks from each plugin might not be invoked. Version 6.0.13 of `firebase_messaging` should resolve this issue so please bump your `firebase_messaging` dependency and follow the steps covered in `firebase_messaging`'s readme file.
 
+##### Scheduled Android notifications
+Some Android OEMs have their own customised Android OS that can prevent applications from running in the background. Consequently, scheduled notifications may not work when the application is in the background on certain devices (e.g. by Xiaomi, Huawei). If you experience problems like this then this would be the reason why. As it's a restriction imposed by the OS, this is not something that can be resolved by the plugin. Some devices may have setting that lets users control which applications run in the background. The steps for these can be vary and but is still up to the users of your application to do given it's a setting on the phone itself.
+
 ##### Recurring Android notifications
 This feature uses the [Alarm Manager](https://developer.android.com/reference/android/app/AlarmManager) API. This is standard practice but does mean the delivery of the notifications/alarms are inexact and this is documented Android behaviour as per the previous link. It has been reported that Samsung's implementation of Android has imposed a maximum of 500 alarms that can be scheduled via this API and exceptions can occur when going over the limit.
 
@@ -63,16 +64,13 @@ Daylight saving issues for scheduled notifications is a known issue. This functi
 ##### Custom notification sounds
 [iOS restrictions](https://developer.apple.com/documentation/usernotifications/unnotificationsound?language=objc) apply (e.g. supported file formats)
 
-
-
 ## 📷 Screenshots
 
 | Android | iOS |
 | ------------- | ------------- |
 | <img height="480" src="https://github.com/MaikuB/flutter_local_notifications/raw/master/images/android_notification.png"> |  <img height="414" src="https://github.com/MaikuB/flutter_local_notifications/raw/master/images/ios_notification.png"> |
 
 
-
 ## 👏 Acknowledgements
 
 * [Javier Lecuona](https://github.com/javiercbk) for submitting the PR that added the ability to have notifications shown daily
@@ -81,8 +79,6 @@ Daylight saving issues for scheduled notifications is a known issue. This functi
 * [Zhang Jing](https://github.com/byrdkm17) for adding 'ticker' support for Android notifications
 * ...and everyone else for their contributions. They are greatly appreciated
 
-
-
 ## 📈 Testing
 
 As the plugin class is not static, it is possible to mock and verify its behaviour when writing tests as part of your application. 
@@ -111,7 +107,6 @@ When specifying the large icon bitmap or big picture bitmap (associated with the
 
 ⚠️ For Android 8.0+, sounds and vibrations are associated with notification channels and can only be configured when they are first created. Showing/scheduling a notification will create a channel with the specified id if it doesn't exist already. If another notification specifies the same channel id but tries to specify another sound or vibration pattern then nothing occurs.
 
-
 #### Scheduled notifications
 
 If your application needs the ability to schedule notifications then you need to request permissions to be notified when the phone has been booted as scheduled notifications uses the `AlarmManager` API to determine when notifications should be displayed. However, they are cleared when a phone has been turned off. Requesting permission requires adding the following to the manifest (i.e. your application's `AndroidManifest.xml` file)
@@ -145,7 +140,7 @@ If the vibration pattern of an Android notification will be customised then add
 For reference, the example app's `AndroidManifest.xml` file can be found [here](https://github.com/MaikuB/flutter_local_notifications/blob/master/flutter_local_notifications/example/android/app/src/main/AndroidManifest.xml)
 
 
-#### Release configurations
+#### Release build configuration
 
 Before creating the release build of your app (which is the default setting when building an APK or app bundle) you will likely need to customise your ProGuard configuration file as per this [link](https://developer.android.com/studio/build/shrink-code#keep-code) and add the following line:
 

flutter_local_notifications/pubspec.yaml

@@ -1,6 +1,6 @@
 name: flutter_local_notifications
 description: A cross platform plugin for displaying and scheduling local notifications for Flutter applications with the ability to customise for each platform.
-version: 1.4.4
+version: 1.4.4+1
 homepage: https://github.com/MaikuB/flutter_local_notifications/tree/master/flutter_local_notifications
 
 dependencies: