Fix `confirmResize` action status code in V2

In server`s action `confirmResize` status code in @wsgi.response
decorator is set as 202 but this is overridden/ignored by return
statement (return exc.HTTPNoContent()) which return 204 status code.

This is very confusing and we should have expected status code in
@wsgi.response decorator as consistence with other APIs.

NOTE- There is no change in API return status code. API returns the
same 204 return code as previously.

Change-Id: Id8033fb8880306babebc14b319bce5b3b8798774
Closes-Bug: #1368597
Merge "Fix `confirmResize` action status code in V2"