Fixing code to address failing tests

Signed-off-by: Kondaka <krishkdk@amazon.com>

Author: kkondaka

data-prepper-core/src/integrationTest/resources/org/opensearch/dataprepper/pipeline/forward-pipeline.yaml

@@ -12,7 +12,8 @@ test-forward-pipeline:
   sink:
     - in_memory:
         testing_key: ForwardPipelineIT
-        forward_to: [ "pipeline2"]
+        forward_to:
+          pipelines: [ "pipeline2"]
 
 pipeline2:
   sink:

data-prepper-pipeline-parser/src/main/java/org/opensearch/dataprepper/pipeline/parser/model/PipelineConfiguration.java

@@ -137,7 +137,8 @@ private static SinkContextPluginSetting getSinkContextPluginSettingFromSinkModel
         final Map<String, Object> settingsMap = Optional
                 .ofNullable(sinkModel.getPluginSettings())
                 .orElseGet(HashMap::new);
-        return new SinkContextPluginSetting(sinkModel.getPluginName(), settingsMap, new SinkContext(sinkModel.getTagsTargetKey(), sinkModel.getRoutes(), sinkModel.getIncludeKeys(), sinkModel.getExcludeKeys(), sinkModel.getForwardConfig().getPipelineNames()));
+        List<String> pipelineNames = sinkModel.getForwardConfig() == null ? null : sinkModel.getForwardConfig().getPipelineNames();
+        return new SinkContextPluginSetting(sinkModel.getPluginName(), settingsMap, new SinkContext(sinkModel.getTagsTargetKey(), sinkModel.getRoutes(), sinkModel.getIncludeKeys(), sinkModel.getExcludeKeys(), pipelineNames));
     }
 
     private Integer getWorkersFromPipelineModel(final PipelineModel pipelineModel) {