Workaround for doze/AOD problem with global wakefulness

When the global wakefulness is dozing and a non-default group
VirtualDisplay wakes up, the global wakefulness becomes awake and the
default display's individual wakefulness remains dozing. But some of
our code in Notifier and PhoneWindowManager that listen to the global
wakefulness kick off a chain of events that results in
KeyguardViewMediator thinking dozing has stopped, and the display gets
stuck in what feels like a sort of half on / half off state where it
shows keyguard at the low brightness and refresh rate we're supposed
to use for AOD, but it isn't responsive to touch inputs.

The workaround in this CL is to restart dreaming in this case to get
the AOD unstuck.

Bug: 187231320
Test: atest PowerManagerServiceTest
Change-Id: I8e348ffe52c7f2d5cbdd11b058254cb087b1021d