Register and update input settings after boot

Some changes input settings have dependencies on other parts of the
system. For example, the show_key_presses setting adds a window to
WM when enabled. To account for this, only register and update input
settings after the system is running.

Bug: 283782679
Test: manual
Change-Id: I622ffdc762537a277f90293eaa1b17b17eae68a2
1 file changed