CTS: add resource file on 280dpi density

Android Oreo (8.0) cts has not assets for 280dpi.
We generated new resources to fix CTS test fail

failed log:
junit.framework.AssertionFailedError: Failed to get resource: /280dpi.zip

Change-Id: I1a8c4e7b4b745b29445b50d02356be4300441835
1 file changed