sepolicy: allow init to mount debugfs in userdebug builds

This change will help debug builds with keeping debugfs
disabled during run time. Instead, debugfs will be mounted by init
to enable boot time initializations to set up debug data collection
and unmounted after boot. It will be also be mounted by dumpstate
for bug report generation and unmounted after.

It resolves the following avc denial:
avc: denied { mounton } for comm="init" path="/sys/kernel/debug" dev="debugfs"
 ino=1 scontext=u:r:init:s0 tcontext=u:object_r:debugfs:s0 tclass=dir permissive=0

Bug: 176936478
Test: make && boot
Change-Id: I5bc819eb0cc36bdc32565c17a16da8838baf946a
1 file changed