Rename conscrypt-module-public-api-stubs-source

Renamed conscrypt-module-public-api-stubs-source to
conscrypt.module.public.api.stubs.source to match the format of the
name created by java_sdk_library.

This is in preparation for switching to use java_sdk_library to
generate conscrypt's public API.

Bug: 153443117
Bug: 153306490
Test: m nothing
Merged-In: I26ad21cf74ad3600de250df8e84deec65b91b3f9
Change-Id: I26ad21cf74ad3600de250df8e84deec65b91b3f9
(cherry picked from commit 29adf462)