Add pointer acceleration native APIs

Bug: 202273865
Test: manual
Change-Id: I61cca8e313f183ff421147d25f11819959e4345a
diff --git a/libs/input/android/os/IInputConstants.aidl b/libs/input/android/os/IInputConstants.aidl
index 829bbdd..265cbf0 100644
--- a/libs/input/android/os/IInputConstants.aidl
+++ b/libs/input/android/os/IInputConstants.aidl
@@ -95,4 +95,7 @@
          */
         INTERCEPTS_STYLUS = 0x00000040,
     }
+
+    /* The default pointer acceleration value. */
+    const int DEFAULT_POINTER_ACCELERATION = 3;
 }