Pass FalsingManager down through more classes.

The CP's http://ag/c/8269205, with some minor modifications.

This removes FalsingManagerFactory, replacing it with
calls to Depedency.get() and pushes those calls further
up the stack in hopes that the FalsingManager can be directly
injected where it's needed in the future.

Contains a few random lint cleanups.

Bug: 136279712
Test: atest SystemUITests
Change-Id: Idd66e40d3bb9ebe9ca583166d5e961cc70ea51b8
Merged-In: Ie24acd33b0d81ae2112aead0c0d5a8658e04994e