accel: rename `accelOobGetDbus` to `getBus`

accelOobGetDbus returns a dbus bus which can be leverage by others.
Rename it to a more common name.

Tested: Unittest passed.
Signed-off-by: Michael Shen <gpgpgp@google.com>
Change-Id: I0e48f7f6a49c09b397d52e9343bc3e32ca41d9d8
diff --git a/handler_impl.hpp b/handler_impl.hpp
index 4a3f5dc..a088585 100644
--- a/handler_impl.hpp
+++ b/handler_impl.hpp
@@ -71,7 +71,7 @@
 
   protected:
     // Exposed for dependency injection
-    virtual sdbusplus::bus::bus accelOobGetDbus() const;
+    virtual sdbusplus::bus::bus getDbus() const;
 
   private:
     std::string _configFile;