change the android build such that Play Store isn't required (also removed android/google-services.json)

BUILDING.md

@@ -1458,17 +1458,18 @@ cd -
 
 - Setup by adding the app/gradle.properties.secrets file (see properties at top
   of app/build.gradle) and the app/time-safari-upload-key-pkcs12.jks file
-- In app/build.gradle, bump the versionCode and maybe the versionName
 - Then `bundleRelease`:
 
 ```bash
 cd android
-./gradlew bundleRelease -Dlint.baselines.continue=true
+./gradlew bundleRelease -Dlint.baselines.continue=true -PfirebaseEnabled
 cd -
 ```
 
 ... and find your `aab` file at app/build/outputs/bundle/release
 
+* Note that F-Droid builds should omit `-PfirebaseEnabled`.
+
 At play.google.com/console:
 
 - Go to Production or the Closed Testing and either Create Track or Manage Track.