Add type alias for DeviceId

To facilitate the future transition to a strong type, add a "weak" type
for DeviceId in this CL.

This will allow us to fix some of the existing code before having to
refactor all of it in a single topic.

Also, in this CL, simplify the names of some variables in TouchState
because we no longer have a conflict with the 'deviceId' member.

Bug: 211379801
Test: none
Change-Id: I1f287ad62fa26ba4bbbbbf353bebfbf8ad38ff67
diff --git a/services/inputflinger/dispatcher/InputState.cpp b/services/inputflinger/dispatcher/InputState.cpp
index fe0b89c..e6941ef 100644
--- a/services/inputflinger/dispatcher/InputState.cpp
+++ b/services/inputflinger/dispatcher/InputState.cpp
@@ -28,7 +28,7 @@
 
 InputState::~InputState() {}
 
-bool InputState::isHovering(int32_t deviceId, uint32_t source, int32_t displayId) const {
+bool InputState::isHovering(DeviceId deviceId, uint32_t source, int32_t displayId) const {
     for (const MotionMemento& memento : mMotionMementos) {
         if (memento.deviceId == deviceId && memento.source == source &&
             memento.displayId == displayId && memento.hovering) {