Remove unused constant

Author: kenzieschmoll

packages/devtools_app/lib/src/service/service_registrations.dart

@@ -54,8 +54,6 @@ const displayRefreshRate = '_flutter.getDisplayRefreshRate';
 
 String get flutterEngineEstimateRasterCache => flutterEngineRasterCache;
 
-const renderFrameWithRasterStats = '_flutter.renderFrameWithRasterStats';
-
 /// Dwds listens to events for recording end-to-end analytics.
 const dwdsSendEvent = 'ext.dwds.sendEvent';