Fix build with latest OpenSearch

OpenSearch recently merged some code that cause buid failure for this
module, as spotted in opensearch-project#585.

This change the import to match the new one after
opensearch-project/OpenSearch#9103

Signed-off-by: Romain Tartière <romain@blogreen.org>

src/main/java/org/opensearch/timeseries/indices/IndexManagement.java

@@ -57,13 +57,13 @@
 import org.opensearch.cluster.metadata.AliasMetadata;
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.cluster.service.ClusterService;
-import org.opensearch.common.Strings;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.common.xcontent.LoggingDeprecationHandler;
 import org.opensearch.common.xcontent.XContentHelper;
 import org.opensearch.common.xcontent.XContentType;
 import org.opensearch.commons.InjectSecurity;
+import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.bytes.BytesArray;
 import org.opensearch.core.xcontent.NamedXContentRegistry;
 import org.opensearch.core.xcontent.XContentParser;

src/main/java/org/opensearch/timeseries/util/RestHandlerUtils.java

@@ -27,10 +27,10 @@
 import org.opensearch.action.search.SearchPhaseExecutionException;
 import org.opensearch.action.search.ShardSearchFailure;
 import org.opensearch.common.Nullable;
-import org.opensearch.common.Strings;
 import org.opensearch.common.xcontent.LoggingDeprecationHandler;
 import org.opensearch.common.xcontent.XContentHelper;
 import org.opensearch.common.xcontent.XContentType;
+import org.opensearch.core.common.Strings;
 import org.opensearch.core.common.bytes.BytesReference;
 import org.opensearch.core.rest.RestStatus;
 import org.opensearch.core.xcontent.NamedXContentRegistry;