Do not audit the fsetid capability for update engine

There's a selinux denial for update_engine after go/aog/530462; the
denial is likely due to the setgid bit of the
update_engine_log_data_file.
Message:
11-11 02:07:54.843   870   870 I auditd  : type=1400 audit(0.0:4): avc:
denied { fsetid } for comm="update_engine" capability=4
scontext=u:r:update_engine:s0 tcontext=u:r:update_engine:s0
tclass=capability permissive=0
11-11 02:07:54.843   870   870 I auditd  : type=1400 audit(0.0:5): avc:
denied { fsetid } for comm="update_engine" capability=4
scontext=u:r:update_engine:s0 tcontext=u:r:update_engine:s0
tclass=capability permissive=0
11-11 02:07:54.843   870   870 I auditd  : type=1400 audit(0.0:4): avc:
denied { fsetid } for comm="update_engine" capability=4
scontext=u:r:update_engine:s0 tcontext=u:r:update_engine:s0
tclass=capability permissive=0
11-11 02:07:54.843   870   870 I auditd  : type=1400 audit(0.0:5): avc:
denied { fsetid } for comm="update_engine" capability=4
scontext=u:r:update_engine:s0 tcontext=u:r:update_engine:s0
tclass=capability permissive=0

Bug: 69197466
Test: denial message gone on sailfish.
Change-Id: I0fdc285e4a4faa8dc37b4907484b3c79d4cc49cf