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
