Revert "SELinux: su: update policies"

This reverts commit 511755d568d6df45d53e419236e3be2a2f4bfb3c.
selinux: Workaround for devices with PR_SET_NO_NEW_PRIVS enforcement

PR_SET_NO_NEW_PRIVS blocks domain transitions from within app_process,
unless the new domain is bounded by the app's context. So we can't
switch to a domain that has perms not available to untrusted_app :(

This means any app can talk to the daemon, bypassing the su executable
client. That's not a good thing, and needs to be resolved.

Change-Id: I85b74f90b8737caaa193a0555b5262e7392519b2
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
selinux: Downgrade TouchControl's domain