Update the display_type field to set custom values

Author: Viktor Pelepiak

slack-base/src/main/java/com/hubspot/slack/client/methods/params/chat/workobject/entity/DisplayType.java

@@ -2,12 +2,9 @@
 
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.databind.PropertyNamingStrategies;
-import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
 import com.fasterxml.jackson.databind.annotation.JsonNaming;
-import com.fasterxml.jackson.databind.annotation.JsonSerialize;
 import com.hubspot.immutables.style.HubSpotStyle;
-import com.hubspot.slack.client.methods.params.chat.workobject.serializers.DisplayTypeDeserializer;
-import com.hubspot.slack.client.methods.params.chat.workobject.serializers.DisplayTypeSerializer;
+import com.hubspot.slack.client.methods.params.chat.workobject.entity.fullsizepreview.FullSizePreview;
 import java.util.Optional;
 import org.immutables.value.Value;
 
@@ -19,12 +16,9 @@ public interface EntityPayloadAttributesIF {
   EntityPayloadAttributeTitle getTitle();
   Optional<String> getDisplayId();
 
-  @JsonInclude(JsonInclude.Include.NON_ABSENT)
-  @JsonSerialize(using = DisplayTypeSerializer.class)
-  @JsonDeserialize(using = DisplayTypeDeserializer.class)
-  Optional<DisplayType> getDisplayType();
-
+  Optional<String> getDisplayType();
   Optional<String> getProductName();
   Optional<Icon> getProductIcon();
   Optional<String> getLocale();
+  Optional<FullSizePreview> getFullSizePreview();
 }