Account for session phase out.

It's possible for "time until quota is consumed" to be positive when
remaining time is 0 since TimingSessions may be phasing out of the
window. Properly account for that in the early returns.

Bug: 218216817
Test: atest FrameworksMockingServicesTests:QuotaControllerTest
Change-Id: I714b3f1bbdbb01c8d45e7b73bd5d2cfa16b29c4e