Add logShowImePostLayoutState

This logs the state in ImeInsetsSourceProvider when we have an on-going
show request that registered an mShowImeRunner, and either a new show
request comes in (cancelling the original one) or a new hide request
comes in (failing the original show).

The new logs should help understand issues where the mShowImeRunner is
registered but not running for a long time (2-3 seconds).

This also adds a line for the dumpsys when the mImeRequester is null.

Bug: 328360239
Test: n/a
Change-Id: I835cf6eeaa1ab1b7cc38481c7c57b478eddb010f