Is there an official page, where this question is answered? In Nov 2016, I am trying to run some Java Bigtable code and it fails on both local dev server and on a real remote instance.
I have tried different versions of both libraries. Appengine either complains about using JMX or running threads. In both cases the usages of these technologies/APIs are deeply internal, being used by Bigtable client core for connection establishment etc.
You can now use Cloud Bigtable from Google App Engine Standard, here is the documentation with a code sample and a complete project.