Update GitHub Actions workflow

.github/workflows/android.yml

@@ -8,18 +8,26 @@ on:
 
 jobs:
   build:
-
     runs-on: ubuntu-latest
-
     steps:
       - uses: actions/checkout@v2
-      - name: set up JDK 1.8
+
+      - name: set up JDK
         uses: actions/setup-java@v1
         with:
-          java-version: 1.8
+          java-version: 11
+
+      - name: Cache Gradle and wrapper
+        uses: actions/cache@v2
+        with:
+          path: |
+            ~/.gradle/caches
+            ~/.gradle/wrapper
+          key: ${{ runner.os }}-gradle-${{ hashFiles('**/*.gradle*') }}
+          restore-keys: |
+            ${{ runner.os }}-gradle-
       - name: Make Gradle executable
         run: chmod +x ./gradlew
+
       - name: Build with Gradle
-        run: ./gradlew build
-      - name: Build Debug APK
-        run: ./gradlew assembleDebug
+        run: ./gradlew build