Move native registries to their own inner classes

Having native methods called in the static initalization of the class
that defines them is problematic for the native registration on host
JVM. This moves the registries into their own inner classes to avoid
this issue.

Bug: 337329128
Test: N/A
Change-Id: Id767661d4da38f53c112bb1376798141b38d2c6c
5 files changed