Remove filterNonTouchAsIs function

Since we are no longer storing hover_exit windows and outside windows in
touch state, we can remove this function.

Bug: 211379801
Test: m inputflinger_tests && $ANDROID_HOST_OUT/nativetest64/inputflinger_tests/inputflinger_tests
Change-Id: I2083a4adb7c5b55656d1010d87557e99b774f462