Guard AConfiguration_getScreenRound.

This was actually added in M, but because it wasn't in the version map
(and there's no CTS test) it's not actually reliably available until
next year...

Bug: https://issuetracker.google.com/146458518
Change-Id: I842aab50f1b383c9b295d3dd1b7dc0ebe79e8aac
1 file changed