[RPP] Fix inverted logic for filtering extension source maps

Fixed: 443286887
Change-Id: I24e63f9b5318462e9646837756f338fe59d55d11
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/6916139
Auto-Submit: Connor Clark <cjamcl@chromium.org>
Reviewed-by: Paul Irish <paulirish@chromium.org>
Commit-Queue: Connor Clark <cjamcl@chromium.org>

Author: Connor Clark

front_end/panels/timeline/TimelinePanel.ts

@@ -1534,7 +1534,7 @@ export class TimelinePanel extends Common.ObjectWrapper.eventMixin<EventTypes, t
     // extensions sourcemaps provide little to no-value for the exported trace
     // debugging, so they are filtered out.
     return metadata.sourceMaps.filter(value => {
-      return value.url && Trace.Helpers.Trace.isExtensionUrl(value.url);
+      return !Trace.Helpers.Trace.isExtensionUrl(value.url);
     });
   }