Build: ASAN in system

Add build system support for asan.tar.bz in the system image. This
is triggered by SANITIZE_TARGET_SYSTEM=true.

Bug: 36458146
Test: m && m SANITIZE_TARGET=true SANITIZE_TARGET_SYSTEM=true
Change-Id: I725f99f16a8c9182b1c7ad26580c73d3708f8554
1 file changed