Use act runner

.gitea/workflows/buildAndroid.yaml

@@ -0,0 +1,16 @@
+name: Build Android
+on: [pull_request, push]
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout the code
+        uses: actions/checkout@v2
+      - name: set up JDK
+        uses: actions/setup-java@v3
+        with:
+          java-version: '17'
+          distribution: 'temurin'
+          cache: gradle
+      - name: Build the app
+        run: ./gradlew build