APEXes can be sanitized

This change first introduces the interface "Sanitizeable" that
module types other than cc.Module can use to be handled by the sanitizer
mutator. APEX module, by implementing the interface, gets sanitizer
variants.

In doing so, sanitizer.go is refactored so that modules have explicit
dependencies to the runtime sanitizer libraries. This allows the runtime
library to be packaged into the APEX when required. This also completes
the dependency graph; updating the prebuilt sanitizer runtime will
trigger rebuilding of modules using the runtime.

Bug: 120894259
Bug: 121038155
Test: SANITIZE_TARGET=hwaddress m apex.test
Test: TARGET_FLATTEN_APEX=true SANITIZE_TARGET=address m
Change-Id: Ia91576ff48cda3c996350308b75bf83fcf7c23d7