Introduce controls on wake lock interface

Change-Id: Ie0ee266e9e6facb2ab2abd652f68765239a41af1
diff --git a/system_server.te b/system_server.te
index 6e1acd3..fd2d130 100644
--- a/system_server.te
+++ b/system_server.te
@@ -45,3 +45,6 @@
 allow system_server cache_backup_file:file relabelto;
 allow system_server apk_private_tmp_file:file relabelto;
 allow system_server wallpaper_file:file relabelto;
+
+# Access to wake locks
+allow system_server sysfs_wake_lock:file rw_file_perms;