Schedule slots for rollup only within catch-up period
Fix nits, increase default catup period to 48hrs
Use absolute timestamp for dropping slots
Add a boolean variable to apply the rollup patch
Merge branches 'chinmay/hotfix_dropping_slots_older_than' and 'chinmay/delayed_metrics_bugfix' into rax-prod

* chinmay/hotfix_dropping_slots_older_than:
  Add a boolean variable to apply the rollup patch
  Use absolute timestamp for dropping slots
  Fix nits, increase default catup period to 48hrs
  Schedule slots for rollup only within catch-up period

* chinmay/delayed_metrics_bugfix:
  Make shard state workers ordering changes
  Make changes to Concurrency Test to account for InMemoryShardStateIO
  Add concurrency test for shard state managers on different ingestion hosts
  Fix the InMemoryShardStateIO used in ShardStateIntegrationTest
  Mark Update stamp as dirty if a higher timestamp slot is not taking an update belonging to lower timestamp and has already been marked as dirty
  Cleanup code and add comments explaining what I am doing Add some comments for what I am doing with the test
  Add slot state convergence test
  Improve MetricsIntegrationTest to reflect the new updateslotsonread logic
  Add comments explaining changes, add another case to SlotUpdateOnRead
  Make both ingest and rollup context push/pull
  First pass at improving the shard state management and rollup scheduling
  Some nits
  Test to prove that rollup fails for delayed metrics