Firebase android proxy setting

There is currently no workaround for using the Android client over a proxy, sorry. I've put this on the Firebase feature list and hopefully we can address it in the near future.

(Answer copied from a previously posted comment)

This article seems to suggest that it is possible. It applies the standard Java proxy directives and one specific one for Google API:

System.setProperty("https.proxyHost", "localhost");
System.setProperty("https.proxyPort", "3128");
System.setProperty("com.google.api.client.should_use_proxy", "true");