fix: bump flutter version in the app release action

Author: Aayush Bisen

.github/workflows/android-release.yml

@@ -37,7 +37,7 @@ jobs:
       - uses: subosito/flutter-action@v1
         with:
           # Adjust to the flutter version you are working with
-          flutter-version: "1.20.4"
+          flutter-version: "2.0.3"
       - name: Get version.txt
         uses: actions/download-artifact@v2
         with: