added build script that detects subprojects in src containing a build.gradle and execute gradle

.gitea/workflows/build_arch.yml

@@ -34,3 +34,8 @@ jobs:
       - name: Start setup process
         run: |
           ./setup.sh
+          ./build.sh
+
+      - name: Copy APKs to host directory
+        run: |
+          cp src/**/build/outputs/apk/**/*.apk /prod/data/apk/