Revert "#1414 fixing intl version to 0.19.0 as that's what the flutter framework depends on (#1415)"

This reverts commit e3469e8.

Author: kmahmood74

pubspec.yaml

@@ -32,7 +32,7 @@ dependencies:
       path: device_preview
 
   yaml: ^3.1.2
-  intl: 0.19.0
+  intl: ^0.18.0
 
   # The following adds the Cupertino Icons font to your application.
   # Use with the CupertinoIcons class for iOS style icons.