sepolicy: address some denials

This is a combination of 3 commits.

sepolicy: allow lhd to create/setattr gps_data_file
sepolicy: allow rild to write to imei_efs_file
sepolicy: allow audioserver to search in efs_file:dir

Change-Id: I699a756eefe0a28b92e82d2be1f6353a048ebfd1