Update GitHub actions workflow.

.github/workflows/main.yml

@@ -7,13 +7,13 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Setup Java 8
-      uses: actions/setup-java@v1.3.0
+      uses: actions/setup-java@v1
       with:
         java-version: 1.8
     - name: Checkout
       uses: actions/checkout@v2
-    - name: Submodule Init
-      run: git submodule sync --recursive && git submodule update --init --force --recursive
+      with:
+        submodules: true
     - name: Build
       run: bash ./gradlew assembleRelease
     - name: Artifact