debuggerd: audit pid, uid and gid on SE Linux denial

When debugging SE Linux audit messages from debuggerd, its
unclear what process is triggering the access violation. To
assist in debugging, we also log pid, uid and gid.

Before:
avc:  denied  { dump_backtrace } for scontext=u:r:dumpstate:s0 ...

After:
avc: denied  { dump_backtrace } for pid=198 uid=1019 gid=1019 ..

Change-Id: I8263e6f5e77917139b73c3e84b76f7f97fd98003
Signed-off-by: William Roberts <william.c.roberts@intel.com>