unfortunatelly, this component is not publicly accessible. I have tried wrapping it in a custom component, however, since it is not documented, there is no way of knowing what attributes to reference in it.
You are better off creating a custom lightning component for your Contact Support Form. I would Recommend using the lightning:recordForm which will handle CRUD, FLS and does not need you to invoke an apex class to manage what fields to use in your form.
Basic usage example:
<lightning:recordEditForm aura:id="recordEditForm"
onsubmit="{!c.handleRecordSubmit}"
objectApiName="Case">
<lightning:inputField fieldName="Subject"/>
<lightning:inputField fieldName="Description" />
<lightning:button aura:id="submit" type="submit" label="Create Case" class="slds-m-top_medium" disabled="true"/>
</lightning:recordEditForm>