[RPP] Add known context value for network dependency tree insight

Bug: 372897712
Change-Id: Ic33806629922771688091616d46884d3b315f65a
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/6316672
Reviewed-by: Jack Franklin <[email protected]>
Auto-Submit: Nancy Li <[email protected]>
Commit-Queue: Jack Franklin <[email protected]>

Author: Nancy Li

front_end/ui/visual_logging/KnownContextValues.ts

@@ -3532,6 +3532,7 @@ export const knownContextValues = new Set([
   'timeline.insights.inp',
   'timeline.insights.lcp-by-phase',
   'timeline.insights.lcp-discovery',
+  'timeline.insights.long-critical-network-tree',
   'timeline.insights.render-blocking-requests',
   'timeline.insights.slow-css-selector',
   'timeline.insights.third-parties',