Upstream keyguard animation flow optimizations

This divides transition flows into separate MutableSharedFlow
per Edge, and also supports (any)->KeyguardState as well as
KeyguardState->(any). This should greatly reduce the number
of continuations as flows will now only get emits directly
for transitions they care about.

Test: atest SystemUITests && perfetto
Bug: 326719188
Flag: N/A
Change-Id: I37402933cd4a45141686e1521fe78d16d6746786