Consolidate logging of global configuration

Post statsd logging to handler to reduce overhead in wm lock.
Also centralize the operations that should execute on handler.
BTW, post a lambda directly is more efficient than PooledLambda.

Bug: 163976519
Flag: EXEMPT simple refactor
Test: CtsWindowManagerDeviceActivity
Change-Id: Ib6276501871ef8a88cb8f300fd1bd7e6b090dda3