UniqueModelTypeRestriction

Do not allow multiple ServingConfigs with same Model.type to be shown on different panels. Example: Panel1 candidates: * pdp_ctr, pdp_cvr, home_page_ctr_no_diversity * Panel2 candidates: * home_page_ctr_no_diversity, home_page_ctr_diversity_low, pdp_cvr_no_diversity * Restriction = UNIQUE_MODEL_RESTRICTION Valid combinations: * * (pdp_ctr, home_page_ctr_no_diversity) * (pdp_ctr, home_page_ctr_diversity) * (pdp_cvr, home_page_ctr_no_diversity) * (pdp_cvr, home_page_ctr_diversity_low) * (home_page_ctr_no_diversity, pdp_cvr_no_diversity) * Invalid combinations: * * (pdp_ctr, pdp_cvr_no_diversity) * (pdp_ctr, pdp_cvr_no_diversity) * (pdp_cvr, pdp_cvr_no_diversity) * (home_page_ctr_no_diversity, home_page_ctr_no_diversity) * (home_page_ctr_no_diversity, home_page_ctr_diversity) *