selinuxrelabel: Remove attempts to relabel /system

These are a no-op due to the additional block-device protection from
https://android.googlesource.com/platform/system/core/+/e18c0d508a6d8b4376c6f0b8c22600e5aca37f69
so get rid of them entirely. Any installing recovery (or equivalent
installation process) should handle the labeling of system components
on its own.

Change-Id: I14c50f08efa6f05b03fad4fbc404219cc504e1ff
TBD: Do we still want to label unlabeled files?
Remove unused audio mk files

These are empty and useless.

Change-Id: I23cd1be105f7bddbf555a35e10efcc92a7c1eb47
Signed-off-by: scott <scott@ubuntu>

Conflicts:
	config/common_full.mk
Merge remote-tracking branch 'upstream/kk44' into kk44