Update rotation active period after schedule changes

What does this MR do?

This updates the on-call rotation's active period times to match it's on-call schedule's new timezone.

We use the existing timezone in order to do the calculations we need to convert the times into the new timezone correctly.

Because of this change, we could introduce overnight shifts. Therefore !57202 (merged) is required to be merged before this one.

Does this MR meet the acceptance criteria?

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Related to #324712 (closed)