Report motion offsets for touchpad swipes

Adds two new axes, AXIS_GESTURE_X_OFFSET and AXIS_GESTURE_Y_OFFSET,
which report the movement of swipe gestures on the touchpad as a
fraction of the touchpad's size.

Bug: 246758376
Test: check axis values come through in a test app
Change-Id: I313410053a8db13273bd05a33d3a6a1f75081dae
diff --git a/services/inputflinger/InputCommonConverter.cpp b/services/inputflinger/InputCommonConverter.cpp
index 23b6f57..6db89d4 100644
--- a/services/inputflinger/InputCommonConverter.cpp
+++ b/services/inputflinger/InputCommonConverter.cpp
@@ -263,8 +263,11 @@
 static_assert(static_cast<common::Axis>(AMOTION_EVENT_AXIS_GENERIC_14) == common::Axis::GENERIC_14);
 static_assert(static_cast<common::Axis>(AMOTION_EVENT_AXIS_GENERIC_15) == common::Axis::GENERIC_15);
 static_assert(static_cast<common::Axis>(AMOTION_EVENT_AXIS_GENERIC_16) == common::Axis::GENERIC_16);
+// TODO(hcutts): add GESTURE_X_OFFSET and GESTURE_Y_OFFSET.
+// If you added a new axis, consider whether this should also be exposed as a HAL axis. Update the
+// static_assert below and add the new axis here, or leave a comment summarizing your decision.
 static_assert(static_cast<common::Axis>(AMOTION_EVENT_MAXIMUM_VALID_AXIS_VALUE) ==
-              static_cast<common::Axis>(AMOTION_EVENT_AXIS_GENERIC_16));
+              static_cast<common::Axis>(AMOTION_EVENT_AXIS_GESTURE_Y_OFFSET));
 
 static common::VideoFrame getHalVideoFrame(const TouchVideoFrame& frame) {
     common::VideoFrame out;