Fix #5658: Update WORKSPACE Java resolution order (#5659)

## Explanation
Fixes #5658

It seems that there was an incompatibility introduced with older
``rules_java`` in the AS Bazel plugin (see
bazelbuild/intellij#6474 for a related issue,
though I'm unsure as to the exact change in the plugin that caused
this).

The fix essentially moves the app's ``rules_java`` initialization (which
_is_ compatible with the plugin) to be before initializing
``oppia_proto_api`` since that uses an old version of ``rules_java``:
https://github.com/oppia/oppia-proto-api/blob/f6d167c5de636edf941e366dc9a6ca6b2bf20e89/repo/versions.bzl#L35-L39.
Since the WORKSPACE resolves as "first declaration wins" the order swap
fixes the issue without introducing any cross-dependency
incompatibilities.

## Essential Checklist
- [x] The PR title and explanation each start with "Fix #bugnum: " (If
this PR fixes part of an issue, prefix the title with "Fix part of
#bugnum: ...".)
- [x] Any changes to
[scripts/assets](https://github.com/oppia/oppia-android/tree/develop/scripts/assets)
files have their rationale included in the PR explanation.
- [x] The PR follows the [style
guide](https://github.com/oppia/oppia-android/wiki/Coding-style-guide).
- [x] The PR does not contain any unnecessary code changes from Android
Studio
([reference](https://github.com/oppia/oppia-android/wiki/Guidance-on-submitting-a-PR#undo-unnecessary-changes)).
- [x] The PR is made from a branch that's **not** called "develop" and
is up-to-date with "develop".
- [x] The PR is **assigned** to the appropriate reviewers
([reference](https://github.com/oppia/oppia-android/wiki/Guidance-on-submitting-a-PR#clarification-regarding-assignees-and-reviewers-section)).

## For UI-specific PRs only
N/A -- this is an infrastructure change only.

WORKSPACE

@@ -16,6 +16,19 @@ android_sdk_repository(
     build_tools_version = BUILD_TOOLS_VERSION,
 )
 
+# The rules_java contains the java_lite_proto_library rule used in the model module.
+http_archive(
+    name = "rules_java",
+    sha256 = HTTP_DEPENDENCY_VERSIONS["rules_java"]["sha"],
+    url = "https://github.com/bazelbuild/rules_java/releases/download/{0}/rules_java-{0}.tar.gz".format(HTTP_DEPENDENCY_VERSIONS["rules_java"]["version"]),
+)
+
+load("@rules_java//java:repositories.bzl", "rules_java_dependencies", "rules_java_toolchains")
+
+rules_java_dependencies()
+
+rules_java_toolchains()
+
 # Oppia's backend proto API definitions.
 git_repository(
     name = "oppia_proto_api",
@@ -75,19 +88,6 @@ bind(
     actual = "//tools:java_toolchain",
 )
 
-# The rules_java contains the java_lite_proto_library rule used in the model module.
-http_archive(
-    name = "rules_java",
-    sha256 = HTTP_DEPENDENCY_VERSIONS["rules_java"]["sha"],
-    url = "https://github.com/bazelbuild/rules_java/releases/download/{0}/rules_java-{0}.tar.gz".format(HTTP_DEPENDENCY_VERSIONS["rules_java"]["version"]),
-)
-
-load("@rules_java//java:repositories.bzl", "rules_java_dependencies", "rules_java_toolchains")
-
-rules_java_dependencies()
-
-rules_java_toolchains()
-
 # The rules_proto contains the proto_library rule used in the model module.
 http_archive(
     name = "rules_proto",