Always initialize local boolean variables when possible

It's currently possible to reference deviceModeChanged in InputReader
while it's in an unknown state. Change the style of initialization
here and a few other places to better prevent this type of error.

(cherry-pick of f583d0dcc6e5c1968c472c844f6c8fbbe036ad78.)

Bug: 11433748
Change-Id: Ic450ca4afe50987b022db9d20bb1cb18ccf060cc
1 file changed