[CM] Remove non-functional timeout from request network

Until now the request network with timeout was non-functional
(see b/31402633). Any caller which was using the timeout getting
the request network without a timeout.

While the timeout version has now been implemented, a max
timeout value is being removed since the large number used
(100 minutes) had no rationale for existing.

Updating the code to reflect the functionality which was
actually used - without a timeout.

Bug: 31399536
Bug: 35354391
Test: unit tests and CTS of ConnectivityManager
Change-Id: I0ebf0917a4478036a5ae532dd1e0784479057eb8