"keepalived" process stops running if it does not find any of the
tracked interfaces correctly configured. To prevent this in
"KeepalivedManagerTestCase" test cases, "eth0" is set up and an IP
address is assigned.
Change-Id: Ibd4ef7b0db5b6830383fffcac685b9c709aae350
Closes-Bug: #1845150
Related-Bug: #1830232
(cherry picked from commit d8eb42f1ea)
(cherry picked from commit eb1d0313d0)