[wiki migration] Android team pages (#148585)

This puts the wiki pages owned by the Android team into the docs/platforms/android directory as planned in [flutter.dev/go/migrate-flutter-wiki-spreadsheet](https://docs.google.com/spreadsheets/d/1x65189ZBdNiLRygpUYoU08pwvXD4M-Z157c6pm8deGI/edit?usp=sharing) 

It also adds the android team labels to the label bot for future PRs.

Changes to the content were only updating cross links, or link to refer to the main branch rather than master.
Remaining links to the wiki will be updated once all other pages have finished moving, they still work in the meantime.

Part of https://github.com/flutter/flutter/issues/145009

.github/labeler.yml

@@ -48,6 +48,11 @@
     - any-glob-to-any-file:
       - examples/api/**/*
 
+'d: docs/':
+  - changed-files:
+    - any-glob-to-any-file:
+      - docs/**/*
+
 'd: examples':
   - changed-files:
     - any-glob-to-any-file:
@@ -126,6 +131,11 @@ package:
     - any-glob-to-any-file:
       - docs/ecosystem/**/*
 
+platform-android:
+  - changed-files:
+    - any-glob-to-any-file:
+      - docs/platform/android/**/*
+
 platform-ios:
   - changed-files:
     - any-glob-to-any-file:
@@ -148,6 +158,11 @@ platform-web:
       - '**/*.expect'
       - '**/*test_fixes*'
 
+team-android:
+  - changed-files:
+    - any-glob-to-any-file:
+      - docs/platform/android/**/*
+
 team-ecosystem:
   - changed-files:
     - any-glob-to-any-file: