CI: upload apk in PR (#1147)

Signed-off-by: Caijinglong <cjl_spy@163.com>

.github/workflows/runnable.yml

@@ -87,6 +87,8 @@ jobs:
     strategy:
       matrix:
         os: [ ubuntu-latest ]
+    permissions: 
+      pull-requests: write
     steps:
       - uses: actions/checkout@v4
       - uses: actions/setup-java@v4
@@ -99,7 +101,28 @@ jobs:
           cache: true
       - run: flutter doctor -v
       - run: flutter pub get
-      - run: cd example; flutter build apk --debug
+      - run: flutter build apk --release
+        name: Build apk
+        working-directory: ${{ github.workspace }}/example
+      - name: Upload artifact
+        uses: actions/upload-artifact@v4
+        id: apk
+        with:
+          if-no-files-found: error
+          path: ${{ github.workspace }}/example/build/app/outputs/flutter-apk/app-release.apk
+          name: app-release-${{github.sha}}.apk
+      - name: comment url in pull request
+        uses: actions/github-script@v4
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          script: |
+            github.issues.createComment({
+              issue_number: context.issue.number,
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              body: 'Download apk from [here](${{ steps.apk.outputs.artifact-url }}) for ${{ github.sha}}'
+            })
+        
 
   test_android_on_windows:
     needs: analyze