[observability_pipelines] Clarify Grok source description (#3207)

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

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

.generator/schemas/v2/openapi.yaml

@@ -46179,7 +46179,7 @@ components:
             $ref: "#/components/schemas/ObservabilityPipelineParseGrokProcessorRuleMatchRule"
           type: array
         source:
-          description: The name of the field in the log event to apply the Grok rules to.
+          description: The value of the source field in log events to be processed by the Grok rules.
           example: "message"
           type: string
         support_rules:

lib/datadog_api_client/v2/models/observability_pipeline_parse_grok_processor_rule.rb

@@ -26,7 +26,7 @@ class ObservabilityPipelineParseGrokProcessorRule
     # Each rule must contain a name and a valid Grok pattern.
     attr_reader :match_rules
 
-    # The name of the field in the log event to apply the Grok rules to.
+    # The value of the source field in log events to be processed by the Grok rules.
     attr_reader :source
 
     # A list of Grok helper rules that can be referenced by the parsing rules.