Update gradle-publish.yml to target main branch

Restrict workflow triggers to main branch for push and pull requests.

.github/workflows/gradle-publish.yml

@@ -3,8 +3,10 @@ name: Build and publish APK
 on:
   workflow_dispatch:
   push:
-    tags:
-      - 'b*'
+    branches: [ "main" ]
+  pull_request:
+    branches: [ "main" ]
+    
 
 env:
   ANDROID_HOME: /usr/local/lib/android/sdk/
@@ -70,4 +72,4 @@ jobs:
         uses: actions/upload-artifact@v7
         with:
           name: app-release
-          path: app-release.apk
+          path: app-release.apk