Add GitHub action to CI

Author: scc-tw

.github/workflows/build.yaml

@@ -0,0 +1,40 @@
+name: gradle build
+
+on: [push]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v3
+      - name: Set up JDK 11
+        uses: actions/setup-java@v3
+        with:
+          java-version: '11'
+          distribution: 'adopt'
+      - name: Validate Gradle wrapper
+        uses: gradle/wrapper-validation-action@e6e38bacfdf1a337459f332974bb2327a31aaf4b
+      - name: Build with Gradle
+        uses: gradle/gradle-build-action@67421db6bd0bf253fb4bd25b31ebb98943c375e1
+        with:
+          arguments: build
+      
+      # https://github.com/mknejp/delete-release-assets
+      - uses: mknejp/delete-release-assets@v1
+        with:
+          token: ${{ github.token }}
+          fail-if-no-assets: false
+          fail-if-no-release: false
+          tag: latest
+          assets: |
+                  ./app/build/outputs/apk/release/app-release-unsigned.apk
+
+      # https://github.com/softprops/action-gh-release
+      - run: cat apk
+      - uses: softprops/action-gh-release@v1
+        with:
+          files: |
+            ./app/build/outputs/apk/release/app-release-unsigned.apk
+          tag_name: "latest"
+          prerelease: true