Migrate CAN bus HAL to nested namespaces

Test: it builds
Change-Id: I83d9ef4f1fff1585e6487c95f09b55b1aa5b3e63
diff --git a/automotive/can/1.0/default/libnetdevice/libnetdevice.cpp b/automotive/can/1.0/default/libnetdevice/libnetdevice.cpp
index fc2b193..aee8205 100644
--- a/automotive/can/1.0/default/libnetdevice/libnetdevice.cpp
+++ b/automotive/can/1.0/default/libnetdevice/libnetdevice.cpp
@@ -25,8 +25,7 @@
 #include <linux/can.h>
 #include <net/if.h>
 
-namespace android {
-namespace netdevice {
+namespace android::netdevice {
 
 bool exists(std::string ifname) {
     return nametoindex(ifname) != 0;
@@ -96,5 +95,4 @@
     return sock.send(req) && sock.receiveAck();
 }
 
-}  // namespace netdevice
-}  // namespace android
+}  // namespace android::netdevice