google#730: Also upload 'libmozcjni.so' as artifacts

This is a follow up to my commit [1], which enabled GitHub Actions
to upload build artifacts for Windows, macOS, and Linux but not for
Android.  This commit is to also support Android.

One interesting requirement for Android is that developers usually need
to build *.so for the following 4 architectures.

 - armeabi-v7a
 - arm64-v8a
 - x86
 - x86_64

With this commit, our GitHub Actions rule actually starts building
'libmozcjni.so' for the above 4 architectures, then archives them into
a single zip file and upload it as the final artifact.

 [1]: bb50663

PiperOrigin-RevId: 561867498

.github/workflows/android.yaml

@@ -32,4 +32,23 @@ jobs:
       - name: build
         working-directory: ./src
         run: |
-          bazel build --config oss_android package
+          mkdir android_artifacts
+          mkdir android_artifacts/armeabi-v7a
+          mkdir android_artifacts/arm64-v8a
+          mkdir android_artifacts/x86
+          mkdir android_artifacts/x86_64
+          bazel build --config oss_android package --cpu=armeabi-v7a
+          cp bazel-bin/android/jni/libmozcjni.so android_artifacts/armeabi-v7a/
+          bazel build --config oss_android package --cpu=arm64-v8a
+          cp bazel-bin/android/jni/libmozcjni.so android_artifacts/arm64-v8a/
+          bazel build --config oss_android package --cpu=x86
+          cp bazel-bin/android/jni/libmozcjni.so android_artifacts/x86/
+          bazel build --config oss_android package --cpu=x86_64
+          cp bazel-bin/android/jni/libmozcjni.so android_artifacts/x86_64/
+
+      - name: upload artifacts
+        uses: actions/upload-artifact@v3
+        with:
+          name: libmozcjni.so
+          path: src/android_artifacts/
+          if-no-files-found: warn