emulator: allows goldfish to disable bootanimation

[    2.447332] type=1400 audit(1512424670.440:8): avc: denied { write } for pid=1408 comm="setprop" name="property_service" dev="tmpfs" ino=1216 scontext=u:r:goldfish_setup:s0 tcontext=u:object_r:property_socket:s0 tclass=sock_file permissive=0
[    2.455350] init: Created socket '/dev/socket/adbd', mode 660, user 1000, group 1000
console:/ $ [    2.470594] init: Service 'ranchu-setup' (pid 1387) killed by signal 1

BUG: 70176291

Change-Id: I309ff3cb89ec01673e84fb275fe795f95711edd6