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 61f5fdf5c907f83f777395b7ebd45432855b5e7b)
diff --git a/apex/ld.config.txt b/apex/ld.config.txt
index a5937fd..af8ec06 100644
--- a/apex/ld.config.txt
+++ b/apex/ld.config.txt
@@ -37,9 +37,11 @@
 
 namespace.platform.isolated = true
 
-namespace.platform.search.paths = /system/${LIB}
+namespace.platform.search.paths  = /system/${LIB}
+namespace.platform.search.paths += /apex/com.android.runtime/${LIB}
 namespace.platform.asan.search.paths  = /data/asan/system/${LIB}
 namespace.platform.asan.search.paths +=           /system/${LIB}
+namespace.platform.asan.search.paths += /apex/com.android.runtime/${LIB}
 
 # /system/lib/libc.so, etc are symlinks to /apex/com.android.lib/lib/bionic/libc.so, etc.
 # Add /apex/... pat to the permitted paths because linker uses realpath(3)