ci: cache ./android/.gradle folder

Author: adil192

.github/workflows/android.yml

@@ -33,6 +33,7 @@ jobs:
           # (https://github.com/actions/runner-images/blob/main/images/ubuntu/Ubuntu2404-Readme.md#android)
           path: |
             .dart_tool/
+            android/.gradle/
             build/
             submodules/flutter/bin/cache/
 
@@ -119,6 +120,7 @@ jobs:
         with:
           path: |
             .dart_tool/
+            android/.gradle/
             build/
             submodules/flutter/bin/cache/
 
@@ -178,6 +180,7 @@ jobs:
         with:
           path: |
             .dart_tool/
+            android/.gradle/
             build/
             submodules/flutter/bin/cache/