Hack to deal with android:pointerIcon in layoutlib

android:pointerIcon is a View attribute that can be an enum or a
reference. Layoutlib cannot easily deal with the way that is handled
in the platform. As the property would not have any impact on the
result in layoutlib, that property is bypassed.

Test: Main.testAllWidgets
Change-Id: I38c6c6df45c1836d44b4f80245a453fb432ea251