NSX: Correct default timeout params

NSX: Correct default timeout params

Previously, req_timeout and http_timeout were set to the same value
which is not correct. req_timeout is the total time limit for a cluster
request and  http_timeout is the time allowed before aborting a request on
an unresponsive controller. Since the default configuration allows 2
retries req_timeout should be double that of http_timeout because of this
this patch goes ahead and removes req_timeout as this should just be
http_timeout * retries.

Because prevouly req_timeout and http_timeout were the same this exposed
a corner case that when the nsx controller returned a 307 we would issue
the request against the redirected controller but in the case where the
session cookie had expire when the request was issued we would get a 401
response back and never retry the request. Now that the default values are
corrected this issue should no longer occur as the next time time we issue
the request we'll fetch a new auth cookie for the redirected controller.

This patch also bumps the timeout values to be higher. We've seen
more and more timeouts occur in our CI system largely because our
cloud is overloaded so increasing the default timeouts will *hopefully*
help reduce test failures.

DocImpact

Closes-bug: 1340969
Closes-bug: 1338846

Change-Id: Id7244cd4d9316931f4f7df1c3b41b3a894f2909a