Add alias as prefix for flavor_rxtx v3

As v3 api rules, the extended attribute should be with extension
alias as prefix. So fix this case for flavor-rxtx v3 extension.

Change-Id: Ie96f88434563e50de4862358be068b975b07cb05
Related-Bug: #1226732
Remove network resources created in scenario tests

Change-Id: I1bd53d99f2632441ebf648cb0c2929c9b55998b6
Closes-Bug: #1274410
Merge "Remove network resources created in scenario tests"
Merge "Add alias as prefix for flavor_rxtx v3"