Migrate CAN bus HAL to nested namespaces

Test: it builds
Change-Id: I83d9ef4f1fff1585e6487c95f09b55b1aa5b3e63
diff --git a/automotive/can/1.0/default/CanBus.h b/automotive/can/1.0/default/CanBus.h
index da3fc5a..8b73258 100644
--- a/automotive/can/1.0/default/CanBus.h
+++ b/automotive/can/1.0/default/CanBus.h
@@ -26,12 +26,7 @@
 #include <atomic>
 #include <thread>
 
-namespace android {
-namespace hardware {
-namespace automotive {
-namespace can {
-namespace V1_0 {
-namespace implementation {
+namespace android::hardware::automotive::can::V1_0::implementation {
 
 struct CanBus : public ICanBus {
     using ErrorCallback = std::function<void()>;
@@ -114,9 +109,4 @@
     ErrorCallback mErrCb;
 };
 
-}  // namespace implementation
-}  // namespace V1_0
-}  // namespace can
-}  // namespace automotive
-}  // namespace hardware
-}  // namespace android
+}  // namespace android::hardware::automotive::can::V1_0::implementation