Add keystore user_changed permission

user_changed will be used for state change methods around android user
creation/deletion.

Change-Id: I295ca9adfc4907b5d7bcf0555f6e5a9a3379635b
diff --git a/access_vectors b/access_vectors
index 65b7e22..e79ad1b 100644
--- a/access_vectors
+++ b/access_vectors
@@ -910,6 +910,7 @@
 	sync_uid
 	password_uid
 	add_auth
+	user_changed
 }
 
 class debuggerd
diff --git a/system_app.te b/system_app.te
index 407b85e..811f436 100644
--- a/system_app.te
+++ b/system_app.te
@@ -73,6 +73,7 @@
 	grant
 	duplicate
 	clear_uid
+	user_changed
 };
 
 control_logd(system_app)
diff --git a/system_server.te b/system_server.te
index d225b7c..961ad86 100644
--- a/system_server.te
+++ b/system_server.te
@@ -393,6 +393,7 @@
 	sync_uid
 	password_uid
 	add_auth
+	user_changed
 };
 
 # Allow system server to search and write to the persistent factory reset