There is difference in VIF list response for v2 and v2.1.
'net_id' attribute is not present in v2.1 VIF list response and
it was added as new microversion - Ic8b26df8d7e69bd71d23dfbc983fa3449c16fa7d
For v21 compatible mode we should have that attribute in response
to make v21 comp mode behaves same as v2.
Also VIF Extension "OS-EXT-VIF-NET" was removed from v2.1 ext list
in - Ic99ac1179d02d907422911fe1369b64479fd5f33
As we need to add 'OS-EXT-VIF-NET:net_id' in VIF
API response to make that same as v2 one. So ext list should have
"OS-EXT-VIF-NET" extension also to avoid any confusion for user whether
this extension is present for v21 comp mode or not.
This commit adds 'OS-EXT-VIF-NET:net_id' attribute in VIF list
response for v21 compatible mode.
Also adds VIF extension in ext list for v21 comp mode.
NOTE-There is no change in v2.1 API.
Closes-Bug #1496664
Change-Id: I4df76fbf85fbb1e79528a1690692b12a65f07835