Switch kernel and init to permissive_or_unconfined().

Switch the kernel and init domains from unconfined_domain()
to permissive_or_unconfined() so that we can start collecting
and addressing denials in -userdebug/-eng builds.

Also begin to address denials for kernel and init seen after
making this switch.

I intentionally did not allow the following denials on hammerhead:
avc:  denied  { create } for  pid=1 comm="init" name="memory.move_charge_at_immigrate" scontext=u:r:init:s0 tcontext=u:object_r:init_tmpfs:s0 tclass=file
avc:  denied  { open } for  pid=1 comm="init" name="memory.move_charge_at_immigrate" dev="tmpfs" ino=6550 scontext=u:r:init:s0 tcontext=u:object_r:init_tmpfs:s0 tclass=file

These occur when init.rc does:
write /sys/fs/cgroup/memory/memory.move_charge_at_immigrate 1
because the prior command to mount the cgroup failed:
mount cgroup none /sys/fs/cgroup/memory memory

I think this is because that cgroup is not enabled in the
kernel configuration.  If the cgroup mount succeeded,
then this would have been a write to a cgroup:file and
would have been allowed already.

Change-Id: I9d7e31bef6ea91435716aa4312c721fbeaeb69c0
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>