Separate network and interface addition/removal netd APIs.
This should facilitate stacked interfaces (i.e. clatd).

Change-Id: Ib3e7a4d3847ef6ec4449451f6da42e75959baa4f
diff --git a/RouteController.cpp b/RouteController.cpp
index e771c74..05170b8 100644
--- a/RouteController.cpp
+++ b/RouteController.cpp
@@ -251,11 +251,13 @@
 #endif
 }
 
-bool RouteController::createNetwork(unsigned netId, const char* interface, Permission permission) {
+bool RouteController::addInterfaceToNetwork(unsigned netId, const char* interface,
+                                            Permission permission) {
     return modifyPerNetworkRules(netId, interface, permission, true, true);
 }
 
-bool RouteController::destroyNetwork(unsigned netId, const char* interface, Permission permission) {
+bool RouteController::removeInterfaceFromNetwork(unsigned netId, const char* interface,
+                                                 Permission permission) {
     return modifyPerNetworkRules(netId, interface, permission, false, true) &&
            flushRoutes(interface);
 }