Use smaller display size for secondary display test.

Some devices might not have enough storage to allocate a large frame
buffer.  Fortunately we don't care how big it is for this test
as long as we can distinguish the secondary display from the primary
display by its properties.

Bug: 19502687
Change-Id: I094b7dbf8650df5bce04ab37a4e32f2be9b20923
2 files changed