Suppress OnNameExpected lint for ComponentCaller APIs in Activity

OnNameExpected asks to rename an API to on<Something> or make it final.

Renaming to on<Something> doesn't make sense for these APIs. Making them
final may introduce inconsistency to other existing methods like
getCallingPackage().

This change also fixes the error message for the getCurrentCaller API.

Bug: 341038044
Test: m checkapi
Flag: EXEMPT bugfix
Change-Id: I628402f4f7b485160c1fcb6b4125ddbb54918900