Improve Synapse variable naming consistency

roles/matrix-synapse/defaults/main.yml

@@ -239,17 +239,17 @@ matrix_s3_media_store_region: "eu-central-1"
 matrix_synapse_self_check_validate_certificates: true
 
 # Controls whether searching the public room list is enabled.
-matrix_enable_room_list_search: true
+matrix_synapse_enable_room_list_search: true
 
 # Controls who's allowed to create aliases on this server.
-matrix_alias_creation_rules:
+matrix_synapse_alias_creation_rules:
   - user_id: "*"
     alias: "*"
     room_id: "*"
     action: allow
 
 # Controls who can publish and which rooms can be published in the public room list.
-matrix_room_list_publication_rules:
+matrix_synapse_room_list_publication_rules:
   - user_id: "*"
     alias: "*"
     room_id: "*"