Add /apex/com.android.runtime/${LIB} to runtime search path.

The canonical location of the HWASAN runtime, an LL-NDK library, is being moved
to the runtime APEX. It is apparently the first LL-NDK library in the runtime
APEX that does not require a legacy symlink in /system/${LIB}. Therefore we
need to add the runtime APEX's ${LIB} directory to the various search paths
used by the linker so that the library can be loaded from the default and
sphal namespaces.

Bug: http://b/134459232
Test: Builds

Change-Id: I1f63e1a2a61e1717d00736ef431f3ec2a9334193
Merged-In: I1f63e1a2a61e1717d00736ef431f3ec2a9334193
(cherry picked from commit 61f5fdf5)