chore: update SOURCE_TYPE symbol description

Author: markostanimirovic

modules/signals/events/src/events-service.ts

@@ -13,7 +13,7 @@ export const EVENTS = Symbol(
   typeof ngDevMode !== 'undefined' && ngDevMode ? 'EVENTS' : ''
 );
 export const SOURCE_TYPE = Symbol(
-  typeof ngDevMode !== 'undefined' && ngDevMode ? 'SOURCE_TYPE' : ''
+  typeof ngDevMode !== 'undefined' && ngDevMode ? 'EVENT_SOURCE_TYPE' : ''
 );
 
 abstract class BaseEvents {