Revert "Make High-Level-Rest-Client tests allow deprecation warning t…

…emporarily, during deprecation of request parameter 'master_timeout' (#2702)" (#2744)

This reverts commit 6a2a33d.

During the process of deprecating REST API request parameter master_timeout and adding alternative parameter cluster_manager_timeout, I made High-Level-Rest-Client tests allow deprecation warning temporarily, by changing the argument of `setStrictDeprecationMode()` to false when building `RestClient` for tests, in the above commit / PR #2702,

This PR sets the High-Level-Rest-Client tests back to treating warning header as a failure.

Signed-off-by: Tianli Feng <ftianli@amazon.com>

test/framework/src/main/java/org/opensearch/test/rest/OpenSearchRestTestCase.java

@@ -824,8 +824,7 @@ protected String getProtocol() {
     protected RestClient buildClient(Settings settings, HttpHost[] hosts) throws IOException {
         RestClientBuilder builder = RestClient.builder(hosts);
         configureClient(builder, settings);
-        // TODO: set the method argument to 'true' after PR https://github.com/opensearch-project/OpenSearch/pull/2683 merged.
-        builder.setStrictDeprecationMode(false);
+        builder.setStrictDeprecationMode(true);
         return builder.build();
     }