ci: add missing channelId

Author: cybex-dev

.github/workflows/flutter-prod.yml

@@ -67,4 +67,5 @@ jobs:
           repoToken: '${{ secrets.GITHUB_TOKEN }}'
           firebaseServiceAccount: '${{ secrets.FIREBASE_SERVICE_ACCOUNT_JS_NOTIFICATIONS_WEB }}'
           projectId: js-notifications-web
+          channelId: live