Allow bluetooth to write to bluetooth properties

Some bluetooth implementations write to bluetooth.* properties.
It seems reasonable to allow this for all bluetooth implementations.

This addresses the following denial (seen on mako):

<4>[  132.182755] avc:  denied  { set } for property=bluetooth.hciattach scontext=u:r:bluetooth:s0 tcontext=u:object_r:bluetooth_prop:s0 tclass=property_service

Change-Id: I6d92c0ff108838dd1107c5fb3c436699ef824814

bluetooth.te

@@ -39,6 +39,9 @@ allow bluetooth proc_bluetooth_writable:file rw_file_perms;
 allow bluetooth sdcard_internal:dir create_dir_perms;
 allow bluetooth sdcard_internal:file create_file_perms;
 
+# Allow write access to bluetooth specific properties
+allow bluetooth bluetooth_prop:property_service set;
+
 ###
 ### Neverallow rules
 ###