Allow installd to dexopt apps on expanded storage.

avc: denied { search } for name="expand" dev="tmpfs" ino=3130 scontext=u:r:installd:s0 tcontext=u:object_r:mnt_expand_file:s0 tclass=dir permissive=0

Bug: 19993667
Change-Id: Ie53df62aa79ae14cd56d7c6f2429b4be382164d1

installd.te

@@ -16,6 +16,7 @@ allow installd oemfs:dir r_dir_perms;
 allow installd oemfs:file r_file_perms;
 allow installd system_file:file x_file_perms;
 allow installd cgroup:dir create_dir_perms;
+allow installd mnt_expand_file:dir search;
 # Check validity of SELinux context before use.
 selinux_check_context(installd)
 # Read /seapp_contexts and /data/security/seapp_contexts