cm: sepolicy: Remove vold external sdcard rules, moved to main sepolicy

Change-Id: I67756bad2c6e1361ecc0052003f2b4e5e4dbb007
selinux: Downgrade CMFM's domain

the filemanager doesn't need to be in platform_app. Put it in untrusted_app,
especially since it's a possible su client

Change-Id: I164853f2c8721d86b5b90677cb33032a3b491ff5