Move build modules from top-level to core/java/

The top-level Android.bp is large and difficult to navigate. Move rules
that don't have any "top level" things in them down in the core/java
directory.

Bug: 185128417
Test: m
Merged-In: I3fd90c2d5140e5716474ff1f8c58cbc1b3319e5b
Change-Id: I3fd90c2d5140e5716474ff1f8c58cbc1b3319e5b