Revert "adding audit_rest_request_method to audit log field reference o…

…pensearch-project#6395"

This reverts commit 20cf86c.

_security/audit-logs/field-reference.md

@@ -40,7 +40,6 @@ Name | Description
 `audit_rest_request_headers` | The HTTP headers, if any.
 `audit_request_initiating_user` | The user that initiated the request. Only logged if it differs from the effective user.
 `audit_request_body` | The HTTP request body, if any (and if request body logging is enabled).
-`audit_rest_request_method` | The HTTP request method.
 
 
 ## REST AUTHENTICATED attributes
@@ -53,7 +52,6 @@ Name | Description
 `audit_rest_request_params` | The HTTP request parameters, if any.
 `audit_rest_request_headers` | The HTTP headers, if any.
 `audit_request_body` | The HTTP request body, if any (and if request body logging is enabled).
-`audit_rest_request_method` | The HTTP request method.
 
 
 ## REST SSL_EXCEPTION attributes