Update android.yml

Author: koogawa

.github/workflows/android.yml

@@ -9,9 +9,5 @@ jobs:
 
     steps:
     - uses: actions/checkout@v1
-    - name: set up JDK 1.8
-      uses: actions/setup-java@v1
-      with:
-        java-version: 1.8
-    - name: Build with Gradle
-      run: ./gradlew build
+    - name: Build debug APK
+        run: ./gradlew :app:assembleDebug