Docs for translucent-vs-transparent-vs-opaque were confusing, especially since the definition for those constants in PixelFormat are not the same as how they're actually used in Drawable. This fix simply adds clarifying text to the method comment for getOpacity(). Issue #21158891 Better document Drawable#getOpacity Change-Id: I94725592f85e5d7874e3a3ac1c5bab969163fbf0