Changes to Update campaign item reviewers

added the new REDUCE_EXPIRATION enum value to the reviews/items/decision/allOf[#/components/schemas/CampaignItemReviewDecisionEnum] response property for the response status 200

added the optional property reviews/items/updated_duration_in_minutes to the response with the 200 status

added the new PRINCIPAL_SELF enum value to the reviews/items/assignment_source response property for the response status 200

added the new PRINCIPAL_SELF enum value to the unassigned_preset_messages/items/assignment_source response property for the response status 200

added the new PRINCIPAL_SELF enum value to the request property to_assign/items/assignment_source/allOf[#/components/schemas/CampaignItemReviewerAssignmentSourceEnum]

added the new PRINCIPAL_SELF enum value to the request property to_remove_sources/items/assignment_source

added the new PRINCIPAL_SELF enum value to the request property to_unassign/items/assignment_source/allOf[#/components/schemas/CampaignItemReviewerAssignmentSourceEnum]

endpoint added