disable dynamic mapping for config index (opensearch-project#2026) (opensearch-project#2028)

disable dynamic mapping for config index
Signed-off-by: Bhavana Ramaram <rbhavna@amazon.com>
(cherry picked from commit 17634b7)

Co-authored-by: Bhavana Ramaram <rbhavna@amazon.com>

Author: opensearch-trigger-bot[bot]

common/src/main/java/org/opensearch/ml/common/CommonValue.java

@@ -355,6 +355,7 @@ public class CommonValue {
                         + "    \"_meta\": {\"schema_version\": "
                         + ML_CONFIG_INDEX_SCHEMA_VERSION
                         + "},\n"
+                        + "    \"dynamic\": \"strict\",\n"
                         + "    \"properties\": {\n"
                         + "      \""
                         + MASTER_KEY