Test cases added for API endpoints used by:
1. host-fs-list
2. host-fs-modify
3. host-fs-show
This commit also fixes the issue of Host FS disk space calculations
yielding different values in Python 2 and Python 3.
Change-Id: I50a1ca43c43c3bba30730c616b3788664920d0c9
Story: 2007082
Task: 38013
Partial-Bug: 1862668
Signed-off-by: Jessica Castelino <jessica.castelino@windriver.com>