Migrate CAN bus HAL to nested namespaces

Test: it builds
Change-Id: I83d9ef4f1fff1585e6487c95f09b55b1aa5b3e63
diff --git a/automotive/can/1.0/default/libnetdevice/can.cpp b/automotive/can/1.0/default/libnetdevice/can.cpp
index 6452d9b..06d45d3 100644
--- a/automotive/can/1.0/default/libnetdevice/can.cpp
+++ b/automotive/can/1.0/default/libnetdevice/can.cpp
@@ -28,9 +28,7 @@
 #include <linux/can/netlink.h>
 #include <linux/can/raw.h>
 
-namespace android {
-namespace netdevice {
-namespace can {
+namespace android::netdevice::can {
 
 static constexpr can_err_mask_t kErrMask = CAN_ERR_MASK;
 
@@ -95,6 +93,4 @@
     return sock.send(req) && sock.receiveAck();
 }
 
-}  // namespace can
-}  // namespace netdevice
-}  // namespace android
+}  // namespace android::netdevice::can