Add only last atop log to snapshot

To minimize the size of Diagnostic snapshot only last atop log will be
added

Related bug: #1389155
This patch should be merged after Ib46ad049bc523f120da1ddaf20fb63a7b135153

Change-Id: I7806a13ff0534f9d139cae27aaf866b3fab11731
Merge "Add only last atop log to snapshot"