This exposes a mechanism for network providers to tell
the network stack that a given network must be kept up
for some specific reason. This is meant to be easier
for them than to have to file a request, in particular
because there is no guaranteed way to make sure the
request will be best matched by any given network.
Test: new test for this
Bug: 167544279
Merged-In: I3c2563d4ae4e3715d0c6270344ba8f7ef067872f
Merged-In: I238a3ee5ee9262477a23b897e4141769dd1505d1
Change-Id: I238a3ee5ee9262477a23b897e4141769dd1505d1
(cherry-picked from ag/13929760)
947acd4275