Fix StaticLayout crash when maxLines = 0

An app setting maxLines = 0 is an edge case, but it can happen. We
had some logic that would index an array at -1 in that case. This
patch just skips the fixup of the ellipsis line break in that case.

Bug: 22353342
Change-Id: I940cf0782b319010f5aedf75b9291df4ac2976d8