Merge changes from topic "b204127880_pipeline_backport_1" into sc-v2-dev

* changes:
  New pipeline: Fix notification re-inflation on dark mode change.
  Make FeatureFlagManager Dumpable
  New Pipeline: Implement lifetime extension for guts
  Add ListenerSet and use in places which currently copy-on-iterate.
  Populate buckets to ensure correct corner rounds on notifications
  Enabled x button for clearable silent Notif[s]
  New pipeline: Section manager is old pipeline, so don't call it for the new.
  Remove dismiss-rtl setters because dismiss is bidirectional
  New pipeline: remove non-silent section headers