Keep mouse pointer hidden while typing

An optimisation causes mouse pointer to remain visible while user is
typing.
As Mouse pointer may reappear while user is typing and may
not hide again if IME connection remains active and touchpad is used.
This leads to an incosistent state where toucpad-pad is disabled but
cursor is visible while user is actively typing on PK.

Bug: 301055381
Test: atest KeyboardInputMapperUnitTest
Change-Id: Id37d57d924e4f1f1b8875b078c48762a5d523acc