When multiple alarm clocks are scheduled at the same time, we would
flap among the alternatives for considering them the 'next upcoming
alarm clock', which in turn would generate [many] spurious broadcasts
about changes to the upcoming alarm situation. This is now fixed;
once we have found the soonest upcoming alarm clock, we stick with
that one until it becomes unavailable, eliminating the spurious
broadcast traffic.
Bug 29501073
Change-Id: Ice1892490bb339e05fa8bd9d324fa1c6718b4942
76389c00d3