Runtime detect HWASan where appropriate

With unbundled HWASan, libraries can be HWASan-ified even if ART is not.
This means we need to detect HWASan at runtime for the stack cleanup
methods, because we cannot be sure that no stack frames are tagged just
because ART does not use HWASan.

Bug: 276930343
Test: flash hwasan build & check apps work
Change-Id: I39c60f98de35c046bb69ab3bf318eaf5d11d4617
2 files changed