Document behavior of absent Splunk sourcetype in Custom Destinations (#3738)

Co-authored-by: ci.datadog-api-spec <packages@datadoghq.com>

Author: api-clients-generation-pipeline[bot]

.generator/schemas/v2/openapi.yaml

@@ -18679,9 +18679,10 @@ components:
           description: |-
             The Splunk sourcetype for the events sent to this Splunk destination.
 
-            If absent, the default sourcetype `_json` is used. If set to null, the `sourcetype`
-            field is omitted from the Splunk HEC payload entirely. Otherwise, the provided string
-            value is used as the sourcetype.
+            If the field is absent from the request and no sourcetype has been previously set on this destination, the default sourcetype `_json` is used.
+            On update, if the field is absent from the request but a sourcetype was previously set, the previous value is kept.
+            If set to `null`, the sourcetype field is omitted from the forwarded event entirely.
+            Otherwise, the provided string value is used as the sourcetype.
           example: my-source
           nullable: true
           type: string
@@ -18964,9 +18965,10 @@ components:
           description: |-
             The Splunk sourcetype for the events sent to this Splunk destination.
 
-            If absent, the default sourcetype `_json` is used. If set to null, the `sourcetype`
-            field is omitted from the Splunk HEC payload entirely. Otherwise, the provided string
-            value is used as the sourcetype.
+            If the field is absent from the request and no sourcetype has been previously set on this destination, the default sourcetype `_json` is used.
+            On update, if the field is absent from the request but a sourcetype was previously set, the previous value is kept.
+            If set to `null`, the sourcetype field is omitted from the forwarded event entirely.
+            Otherwise, the provided string value is used as the sourcetype.
           example: my-source
           nullable: true
           type: string

src/main/java/com/datadog/api/client/v2/model/CustomDestinationForwardDestinationSplunk.java

@@ -105,9 +105,11 @@ public CustomDestinationForwardDestinationSplunk sourcetype(String sourcetype) {
   /**
    * The Splunk sourcetype for the events sent to this Splunk destination.
    *
-   * <p>If absent, the default sourcetype <code>_json</code> is used. If set to null, the <code>
-   * sourcetype</code> field is omitted from the Splunk HEC payload entirely. Otherwise, the
-   * provided string value is used as the sourcetype.
+   * <p>If the field is absent from the request and no sourcetype has been previously set on this
+   * destination, the default sourcetype <code>_json</code> is used. On update, if the field is
+   * absent from the request but a sourcetype was previously set, the previous value is kept. If set
+   * to <code>null</code>, the sourcetype field is omitted from the forwarded event entirely.
+   * Otherwise, the provided string value is used as the sourcetype.
    *
    * @return sourcetype
    */

src/main/java/com/datadog/api/client/v2/model/CustomDestinationResponseForwardDestinationSplunk.java

@@ -79,9 +79,11 @@ public CustomDestinationResponseForwardDestinationSplunk sourcetype(String sourc
   /**
    * The Splunk sourcetype for the events sent to this Splunk destination.
    *
-   * <p>If absent, the default sourcetype <code>_json</code> is used. If set to null, the <code>
-   * sourcetype</code> field is omitted from the Splunk HEC payload entirely. Otherwise, the
-   * provided string value is used as the sourcetype.
+   * <p>If the field is absent from the request and no sourcetype has been previously set on this
+   * destination, the default sourcetype <code>_json</code> is used. On update, if the field is
+   * absent from the request but a sourcetype was previously set, the previous value is kept. If set
+   * to <code>null</code>, the sourcetype field is omitted from the forwarded event entirely.
+   * Otherwise, the provided string value is used as the sourcetype.
    *
    * @return sourcetype
    */