ConnectivityManager: allow usage of TYPE_NONE

This patch allows to use TYPE_NONE for the legacy network type variable
of NetworkInfo. This usage is "safe" with respect to legacy APIs using
network types as most of them already returns null or do nothing for
TYPE_NONE.

Of the existing APIs in ConnectivityManager that accept a network type
argument, those which were already returning null or doing nothing for
TYPE_NONE are:
  getNetworkInfo(int)
  getNetworkForType(int)
  stopUsingNetworkFeature(int, String)
  networkCapabilitiesForType(int)
  requestRouteToHostAddress(int, InetAddress)
  reportInetCondition(int, int)
  isNetworkSupported(int)
  getLinkProperties(int)

Only setProvisioningNotificationVisible needs an additional guard
against TYPE_NONE.

Bug: 30088447
Bug: 62844794
Test: runtest frameworks-net
Change-Id: I4455f2726d06406047086368628c1f253d854d8d