Migrate CAN bus HAL to nested namespaces

Test: it builds
Change-Id: I83d9ef4f1fff1585e6487c95f09b55b1aa5b3e63
diff --git a/automotive/can/1.0/default/libnetdevice/NetlinkRequest.h b/automotive/can/1.0/default/libnetdevice/NetlinkRequest.h
index ba9b65b..3e28d78 100644
--- a/automotive/can/1.0/default/libnetdevice/NetlinkRequest.h
+++ b/automotive/can/1.0/default/libnetdevice/NetlinkRequest.h
@@ -21,8 +21,7 @@
 
 #include <string>
 
-namespace android {
-namespace netdevice {
+namespace android::netdevice {
 
 typedef unsigned short rtattrtype_t;  // as in rtnetlink.h
 typedef __u16 nlmsgtype_t;            // as in netlink.h
@@ -151,5 +150,4 @@
     }
 };
 
-}  // namespace netdevice
-}  // namespace android
+}  // namespace android::netdevice