Fix cluster settings to activate mcp protocol (#10862)

Since version 3.1, activating mcp protocol is done trough "plugins.ml_commons.mcp_connector_enabled"

Signed-off-by: pietro-A2lean <[email protected]>

Author: pietro-A2lean

_ml-commons-plugin/agents-tools/mcp/mcp-connector.md

@@ -23,7 +23,7 @@ Before using MCP tools, you must complete the following prerequisites.
 
 ### Enable MCP and configure trusted connector endpoints
 
-- Enable the MCP protocol by configuring the `plugins.ml_commons.mcp_feature_enabled` setting.
+- Enable the MCP protocol by configuring the `plugins.ml_commons.mcp_connector_enabled` setting.
 - Configure trusted connector endpoints in the `plugins.ml_commons.trusted_connector_endpoints_regex` setting. For security purposes, this setting uses regex patterns to define which MCP server URLs are allowed.
 
 To configure both settings, send the following request:
@@ -35,7 +35,7 @@ POST /_cluster/settings/
     "plugins.ml_commons.trusted_connector_endpoints_regex": [
       "<mcp server url>"
     ],
-    "plugins.ml_commons.mcp_feature_enabled": "true"
+    "plugins.ml_commons.mcp_connector_enabled": "true"
   }
 }
 ```
@@ -251,4 +251,4 @@ The agent uses both the OpenSearch tools specified in the `tools` array and the
 ## Additional resources
 
 * For more information about the MCP protocol, see [MCP protocol documentation](https://modelcontextprotocol.io/introduction).
-* For information about using MCP in Java, see [MCP Java SDK](https://github.com/modelcontextprotocol/java-sdk).
+* For information about using MCP in Java, see [MCP Java SDK](https://github.com/modelcontextprotocol/java-sdk).