[lib] Handle messageStorePruneActionType in reduceThreadActivity
Summary:
We want to upsert lastPruned for threadIDs included in messageStorePruneActionType payload in threadActivityStore.
Depends on D9404
Test Plan:
- Modify pruning code to run every minute
- Observe that lastPruned inside threadActivityStore gets set as expected on messageStorePruneActionType
Reviewers: ashoat, ginsu, tomek
Reviewed By: ashoat
Subscribers: wyilio
Differential Revision: https://phab.comm.dev/D9406