message: Revise unit test for XML pass_by attribute
diff: <comment>Example scalar arg, pass by reference</comment>
  </arg>
  <arg name="Arg3" type="U32">
  - <comment>Example scalar arg, pass by value (default)</comment>
  + <comment>Example scalar arg, pass by default</comment>
  </arg>
  <arg name="Arg4" type="ExampleType" pass_by="pointer">
  <comment>Example object arg, pass by pointer</comment>
  <comment>Example object arg, pass by reference</comment>
  </arg>
  <arg name="Arg6" type="ExampleType">
  - <comment>Example object arg, pass by const reference (default)</comment>
  + <comment>Example object arg, pass by default</comment>
  </arg>
  <arg name="Arg7" type="string" size="5" pass_by="pointer">
  <comment>Example string arg, pass by pointer</comment>
  <comment>Example string arg, pass by reference</comment>
  </arg>
  <arg name="Arg9" type="string" size="5">
  - <comment>Example string arg, pass by const reference (default)</comment>
  + <comment>Example string arg, pass by default</comment>
  </arg>
  </args>
  </interface>
  