Consolidate the CursorShape constants in wayland_cursor.h

Reorganize code in base to export header:
  * android_runtime/android_view_PointerIcon.h

and utilize this file in wayland_service_aidl module to consolidate and
DRY the codebase somewhat.

BUG: b/177040175
Test: Modified tests to use the shared enum after removing the old one.

Change-Id: I27420c48c324dffcd8ba507cae2bccbf9b4f4142