Add swap measurement unit (MB) to CLI output

The measurement unit of the swap memory in flavor is MB.
If not clearly labeled, some may confuse it with other disk's
units which are GB.

Closes-Bug: #1323541
Change-Id: I29b4c8e14bcdb3505d5c0bae8bcf653c96b27413
Merge "Add swap measurement unit (MB) to CLI output"