Use struct android_net_context when interfacing with bionic

Add a new NetworkController::getNetworkContext() that builds the
contents of a struct net_context out of getNetworkForConnect()
and getNetworkForDns().

Bug: 19470192
Bug: 20733156
Bug: 21832279
Change-Id: I5a69b0413a83d33be28b78c0a99359b109517a8f
4 files changed
tree: 15f4c089c1edf5fe8210f81a999ef9eaf6c732ec
  1. client/
  2. include/
  3. server/
  4. Android.mk