ci: add secret.properties setup to handle secrets in ci workflow

This fetches the secrets from GitHub Secrets and pastes them into the template file `secrets.defaults.properties`. This file is then copied over to a `secrets.properties` created in the CI.
This ensures proper and secure secrets handling.

.github/workflows/ci.yml

@@ -87,6 +87,19 @@ jobs:
         run: |
           chmod +x ./gradlew
 
+      - name: Setup secrets.properties
+        env:
+          SUPABASE_KEY: ${{ secrets.SUPABASE_KEY }}
+          SERVICE_KEY: ${{ secrets.SERVICE_KEY }}
+          SUPABASE_URL: ${{ secrets.SUPABASE_URL }}
+          POWERSYNC_URL: ${{ secrets.POWERSYNC_URL }}
+        run: |
+          sed -e "s|SAFE_DEFAULT_VALUE_SERVICE_KEY|$SERVICE_KEY|g;" \
+              -e "s|SAFE_DEFAULT_VALUE_SUPABASE_KEY|$SUPABASE_KEY|g;" \
+              -e "s|SAFE_DEFAULT_VALUE_SUPABASE_URL|$SUPABASE_URL|g;" \
+              -e "s|SAFE_DEFAULT_VALUE_POWERSYNC_URL|$POWERSYNC_URL|g;" secrets.defaults.properties > secrets.properties
+
+
       # Check formatting
       - name: KTFmt Check
         run: |