Remove references to UI.GetCapabilities response parameter systemCapabilities.displayCapabilities

[iCollin]

Bug Report

Core and the SDL HMI have code to handle a parameter which is not in the spec.

According to the HMI API, the UI.GetCapabilities response parameter systemCapabilities is of type Common.SystemCapabilities:

<function name="GetCapabilities" messagetype="response">
    ...
    <param name="systemCapabilities" type="Common.SystemCapabilities" mandatory="false">
    ...

https://github.com/smartdevicelink/sdl_core/blob/develop/src/components/interfaces/HMI_API.xml#L5816

For reference here is the complete Common.SystemCapabilities definition:

  <struct name="SystemCapabilities">
      <param name="navigationCapability" type="Common.NavigationCapability" mandatory="false">
      </param>
      <param name="phoneCapability" type="Common.PhoneCapability" mandatory="false">
      </param>
      <param name="videoStreamingCapability" type="Common.VideoStreamingCapability" mandatory="false">
      </param>
      <param name="driverDistractionCapability" type="Common.DriverDistractionCapability" mandatory="false">
        <description>Describes capabilities when the driver is distracted</description>
      </param>
  </struct>

https://github.com/smartdevicelink/sdl_core/blob/develop/src/components/interfaces/HMI_API.xml#L3832

It seems the type was mistaken for a similarly named type, but unlike Common.SystemCapability, Common.SystemCapabilities has no member displayCapabilities.

Core attempts to access a field at msg_params["systemCapabilities"]["displayCapabilities"] here. The SDL HMI also attempts to provide this field here.

Expected Changes

Since this parameter is not in the API spec, there should not be code for it.

[iCollin]

Closed via #3746