Added the workflow for building the APK

.github/workflows/android-build.yml

@@ -0,0 +1,39 @@
+name: Android Build
+
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v2
+
+      - name: Set up Node.js
+        uses: actions/setup-node@v2
+        with:
+          node-version: '14'
+
+      - name: Install dependencies
+        run: npm install
+
+      - name: Set up JDK
+        uses: actions/setup-java@v2
+        with:
+          distribution: 'adopt'
+          java-version: '11'
+
+      - name: Build APK
+        run: cd android && ./gradelew assembleRelease
+
+      - name: Upload APK
+        uses: actions/upload-artifact@v2
+        with:
+          name: app-release.apk 
+          path: android/app/build/outputs/apk/release/app-release-unsigned.apk 
+
+