Wrap InterfaceController into the android::net namespace

No functionality changes, this is a cleanup.

Test: m netd_unit_test
Change-Id: I5c6667051b7b4b17171e6dcc6883f17db08eaa23
diff --git a/server/InterfaceController.cpp b/server/InterfaceController.cpp
index 4c35085..7006fee 100644
--- a/server/InterfaceController.cpp
+++ b/server/InterfaceController.cpp
@@ -192,6 +192,9 @@
 
 }  // namespace
 
+namespace android {
+namespace net {
+
 android::netdutils::Status InterfaceController::enableStablePrivacyAddresses(
         const std::string& iface,
         const GetPropertyFn& getProperty,
@@ -439,3 +442,6 @@
     }
     return ifacePairs;
 }
+
+}  // namespace net
+}  // namespace android