Allow WallpaperManager to return desired size of 0

The documentation for WallpaperManager allows it to return
0 for getDesiredMinimum{Width|Height}. In this case, the caller
should assume the size of the default display. The test
did not expect this case.

Bug:14993886
Change-Id: I2912218c17939c468b55da01748970be52f52601
1 file changed