Closes #8209 - Use new onTouchEventForResult GV api
Changes: - previously NestedGV#onTouchEvent event would call onTouchEventForResult where we would make possible the integration of GV in CoordinatorLayout. Since NestedGV#onTouchEvent does not anymore call onTouchEventForResult I've moved all code in onTouchEvent and then call onTouchEventForResult only for ACTION_DOWN events as snorp recommended. - we now must wait for onTouchEventForResult#GeckoResult<Int> and only then call startNestedScroll(..) since otherwise when executing that method in BrowserToolbarBottomBehavior we would return false since the MotionEvent is at that time unhandled. - only dispatch startNestedScroll and dispatchNestedPreScroll if GV returned INPUT_RESULT_HANDLED. - Ignored "ClickableViewAccessibility" since NestedGeckoView is not intented to be clickable, but rather the elements from the webpage displayed. In testing I saw most of the times GeckoResult resolves in < 5ms with bigger timeouts showing a logarithmic growth. As such I think the change should be imperceptible to users.