Port to Beryllium: Proguard rules are not sufficient

This post in the forums points out that my original proguard rules are insufficient.

https://www.couchbase.com/forums/t/unsatisfiedlinkerror-on-android/36471

I've created
https://github.com/couchbase/docs-couchbase-lite/pull/815
https://issues.couchbase.com/browse/DOC-11250

To address the issue in the documentation.  This ticket addresses updating the consumer-proguard.pro files