Add full license headers to EntityConfig and EntityConfigTest

Signed-off-by: Nikhil Bagmar <nikhilbagmar73@gmail.com>

Author: bagmarnikhil

data-prepper-plugins/cloudwatch-logs/src/main/java/org/opensearch/dataprepper/plugins/sink/cloudwatch_logs/config/EntityConfig.java

@@ -1,6 +1,11 @@
 /*
  * Copyright OpenSearch Contributors
  * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ *
  */
 
 package org.opensearch.dataprepper.plugins.sink.cloudwatch_logs.config;

data-prepper-plugins/cloudwatch-logs/src/test/java/org/opensearch/dataprepper/plugins/sink/cloudwatch_logs/config/EntityConfigTest.java

@@ -1,6 +1,11 @@
 /*
  * Copyright OpenSearch Contributors
  * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ *
  */
 
 package org.opensearch.dataprepper.plugins.sink.cloudwatch_logs.config;