fix publish to docker hub (#96)

.github/workflows/publish.yml

@@ -4,12 +4,10 @@ on:
     types: [published]
 
 jobs:
-  push_to_registry:
-    name: Push Docker image to Docker Hub
+  publish_to_dockerhub:
+    name: Publish to Docker Hub
     runs-on: ubuntu-20.04
-    env:
-      DOCKER_IMAGE: reactnativecommunity/react-native-android
-    if: ${{ startsWith(github.ref, 'refs/tags/v*') }}
+    if: ${{ startsWith(github.ref, 'refs/tags/v') }}
     steps:
       - name: Check out the repo
         uses: actions/checkout@v2
@@ -24,12 +22,14 @@ jobs:
           password: ${{ secrets.DOCKER_PASSWORD }}
 
       - name: Prepare tags
+        env:
+          DOCKER_IMAGE: reactnativecommunity/react-native-android
         id: tags
         run: |
           VERSION=${GITHUB_REF#refs/tags/v}
           echo ::set-output name=tags::"${DOCKER_IMAGE}:${VERSION},${DOCKER_IMAGE}:latest"
 
-      - name: Push to Docker Hub
+      - name: Build & publish to Docker Hub
         uses: docker/build-push-action@v2
         with:
           push: true