mock firmware assets for release

.github/workflows/release.yml

@@ -76,6 +76,11 @@ jobs:
 #        unzip -qq ./firmware.zip 'littlefs-*.bin' 'firmware-heltec*.bin' 'firmware-tbeam*.bin' 'firmware-tlora*.bin' 'firmware-nano*.bin' -d ./app/src/main/assets/firmware
 #        rm ./firmware.zip
 
+    - name: Mock firmware assets for release
+      run: |
+        rm -rf ./app/src/main/assets/firmware
+        mkdir -p ./app/src/main/assets/firmware
+
     - name: Validate Gradle wrapper
       uses: gradle/wrapper-validation-action@v1