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/TetherController.cpp b/server/TetherController.cpp
index c086465..84bab0a 100644
--- a/server/TetherController.cpp
+++ b/server/TetherController.cpp
@@ -49,6 +49,9 @@
 #include "ResponseCode.h"
 #include "TetherController.h"
 
+namespace android {
+namespace net {
+
 using android::base::Join;
 using android::base::StringAppendF;
 using android::base::StringPrintf;
@@ -112,9 +115,6 @@
 
 }  // namespace
 
-namespace android {
-namespace net {
-
 auto TetherController::iptablesRestoreFunction = execIptablesRestoreWithOutput;
 
 const int MAX_IPT_OUTPUT_LINE_LEN = 256;