Address adb backup/restore denials.

Resolves the following denials seen during an adb backup and restore
sequence.

<5>[   90.247039] type=1400 audit(1388759567.693:16): avc:  denied  { getopt } for  pid=3503 comm="Thread-149" scontext=u:r:system_server:s0 tcontext=u:r:adbd:s0 tclass=unix_stream_socket
<5>[   90.249176] type=1400 audit(1388759567.703:17): avc:  denied  { getopt } for  pid=2334 comm="app_process" scontext=u:r:shell:s0 tcontext=u:r:adbd:s0 tclass=unix_stream_socket

Change-Id: I1f6f90f29eecc32ee692764b04b812988f099cde
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>