sepolicy:Add oemfs ruler for carrier switch

  1.Carrier overlay apk could be found and loaded in oemfs
  2.Carrier Link file could be found in oemfs,such as "lib.so.link"

Change-Id: I9a32329e23363087b3a49baeeb3c3f8390a8116a
CRs-Fixed: 1086459
5 files changed