Fix meteredness bugs in updateNetworkRulesNL().

The logic in that method appears to have become broken at some
point; refactor it to apply all known network policies, and then
perform one last pass to handle any metered networks that didn't
have policies; typically Wi-Fi networks.

Test: cts-tradefed run commandAndExit cts-dev -m CtsHostsideNetworkTests
Bug: 64274313
Change-Id: Id9cbcc6fdfe3793e058f52505c9edd250bed7089