Handle NEVER-but-elevated-bucket case.

There are situations where an app is in the NEVER bucket but has its
effective standby bucket elevated. In that case, the app will have 0
expedited job quota without running any EJs, so the start alarm
scheduling should acknowledge that case.

Bug: 171305774
Bug: 175772165
Test: atest FrameworksMockingServicesTests:QuotaControllerTest
Test: atest CtsJobSchedulerTestCases
Change-Id: I905ea210a882d310e33ecb63198173aa9f2dd9c1