Mostly to add test to assure the corner cases are covered.
One minor logic change is if two true conditions happen, in the case
when following happen:
(bucket boundary1) -> (condition false) -> (condition true) -> (pull
triggered for the boundary1)
Previously we take the latest. Now we skip the late boundary pull.
Bug: 76384731
Test: unit test
Change-Id: I345c2210a58bf03eb91d65742573073d2668358b
6d370f40fe