Add support for hiding settings based on whether features are enabled in the license.

awx/conf/conf.py

@@ -78,6 +78,9 @@ register(
     # the other settings change, the cached value for this setting will be
     # cleared to require it to be recomputed.
     depends_on=['ANSIBLE_COW_SELECTION'],
+    # Optional; licensed feature required to be able to view or modify this
+    # setting.
+    feature_required='rebranding',
 )
 
 register(