WindowManagerService: Fix On-Screen keyboard popups when hw-keyboard is present

This fixes the issue with the On-Screen keyboard popping up when users
with a hardware keyboard select a text input field.  The original line of
"mShowImeWithHardKeyboard = hardKeyboardAvailable" is unwarranted and the
call to updateShowImeWithHardKeyboard() was redundant.

Change-Id: Ibf3f05762e72077bbe7946f83b0e320bb94a06c5