Add /data/lib64, /data/vendor/lib64 to ASan sepolicy.

This policy takes effect only when building with
SANITIZE_TARGET=address and allows the Zygote to load libraries from
/data. That's where ASan-instrumented copies of system libraries are
located. 32-bit library directories have been added a while back;
this CL extends the same policy to 64-bit directories.

Bug: 25751174
Bug: 28680288

(cherry picked from commit dda55908)

Change-Id: Ieb4701b78db9649ec8563f2962a69db537ae61b3

file_contexts_asan

 /data/lib(/.*)?                u:object_r:system_file:s0
+/data/lib64(/.*)?              u:object_r:system_file:s0
 /data/vendor/lib(/.*)?         u:object_r:system_file:s0
+/data/vendor/lib64(/.*)?       u:object_r:system_file:s0