g2: Completely remove GestureSettings

We don't support cmhw tunable framework, so why keep it around? Init
other changes are just so that knock on can be toggled from framework,
but since we lack that setting, there is no need for any of these
changes.

Change-Id: Ifb3565cfc3aa9d5a6a56b7ca377ab677787d43a6
Signed-off-by: Rohan Mathur <rohanmathur34@gmail.com>