Allow untrusted_app to list services.

CTS relies on the ability to see all services on the system to make sure
the dump permission is properly enforced on all services.  Allow this.

Bug: 23476772
Change-Id: I144b825c3a637962aaca59565c9f567953a866e8

untrusted_app.te

@@ -80,6 +80,9 @@ allow untrusted_app mnt_media_rw_file:dir search;
 allow untrusted_app cache_file:dir create_dir_perms;
 allow untrusted_app cache_file:file create_file_perms;
 
+# allow cts to query all services
+allow untrusted_app servicemanager:service_manager list;
+
 allow untrusted_app drmserver_service:service_manager find;
 allow untrusted_app mediaserver_service:service_manager find;
 allow untrusted_app nfc_service:service_manager find;