Fix showing keyboard without editor focused in some cases (1-2/2)

As CL[1] mentioned window focus behavior changes from R,
ignoring STATE_VISIBLE or STATE_ALWAYS_VISIBLE request doesn't enough
to fix unexpected keyboard visible issue when same window focused with
the above softInput flag without editor focus, since there is no
additional unspecified window focus to hide the current soft-input
as prior to R's behavior.

To fix that, we introduced new SoftInputShowHideReason to hide
soft-input when the same window focused without valid editor focus
after screen unlock, in order to align with the behavior prior to R.

[1]: I37ae6e30d1de581ba15131c2a90396b3a522a4d6

Bug: 161506356
Test: atest CtsInputMethodTestCases
Change-Id: I20e8076acc5fec3c055af0740e2e2a64b1fb6f0d