Use JDK 11 in Github CI

Author: yaraki

.github/workflows/android.yml

@@ -28,10 +28,10 @@ jobs:
 
     steps:
       - uses: actions/checkout@v1
-      - name: set up JDK 1.8
+      - name: set up JDK 11
         uses: actions/setup-java@v1
         with:
-          java-version: 1.8
+          java-version: 11
       - name: Build project
         run: .github/scripts/gradlew_recursive.sh assembleDebug
       - name: Zip artifacts