Remove setInflationCallback

The current use cases for NotificationRowBinderImpl and NotifInflater's
API don't really need a persistent inflation callback stored as opposed
to a one-shot callback. By explicitly putting the callback in the
inflate methods, it also makes it more clear which calls inflate and
expect a callback to be called.

Bug: 145749521
Test: atest SystemUITests
Test: smoke test (add, update, remove notification)
Change-Id: I001413f17b7472ea2ef637be21d9d454ee17015e