Add Android CI workflow

.github/workflows/android.yml

@@ -0,0 +1,41 @@
+name: Android CI
+
+on: [ push, pull_request ]
+
+jobs:
+  build:
+    name: Build
+    runs-on: ubuntu-20.04
+
+    steps:
+    - uses: actions/checkout@v2
+
+    - name: Set up JDK 11
+      uses: actions/setup-java@v2
+      with:
+        distribution: 'temurin'
+        java-version: '11'
+
+    - name: Validate Gradle Wrapper
+      uses: gradle/wrapper-validation-action@v1
+
+    - name: Build and run tests
+      run: ./gradlew build
+      env:
+        ORG_GRADLE_PROJECT_ci: 1
+
+    - name: Log checksums
+      run: sha256sum native-utils/build/outputs/aar/*
+
+    - name: Upload artifacts
+      uses: actions/upload-artifact@v2
+      with:
+        name: native-utils-aar
+        path: native-utils/build/outputs/aar
+
+    - name: Publish to GitHub Packages
+      if: startsWith(github.ref, 'refs/tags/v')
+      run: ./gradlew publishAllPublicationsToGitHubPackagesRepository
+      env:
+        ORG_GRADLE_PROJECT_ci: 1
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}