Correctly format arrays in output

There are a few places where arrays are output in messages yet the
output would merely use the default toString implementation rather than
actually putting the content of the array in the message. This commit
fixes the issue.

Relates #24340

core/src/main/java/org/elasticsearch/search/aggregations/bucket/sampler/SamplerAggregator.java

@@ -33,6 +33,7 @@ import org.elasticsearch.search.aggregations.support.ValuesSource;
 import org.elasticsearch.search.internal.SearchContext;
 
 import java.io.IOException;
+import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
 
@@ -114,7 +115,7 @@ public class SamplerAggregator extends SingleBucketAggregator {
                     return mode;
                 }
             }
-            throw new IllegalArgumentException("Unknown `execution_hint`: [" + value + "], expected any of " + values());
+            throw new IllegalArgumentException("Unknown `execution_hint`: [" + value + "], expected any of " + Arrays.toString(values()));
         }
 
         private final ParseField parseField;

core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/SignificantTermsAggregatorFactory.java

@@ -53,6 +53,7 @@ import org.elasticsearch.search.aggregations.support.ValuesSourceConfig;
 import org.elasticsearch.search.internal.SearchContext;
 
 import java.io.IOException;
+import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
 
@@ -327,7 +328,7 @@ public class SignificantTermsAggregatorFactory extends ValuesSourceAggregatorFac
                     return mode;
                 }
             }
-            throw new IllegalArgumentException("Unknown `execution_hint`: [" + value + "], expected any of " + values());
+            throw new IllegalArgumentException("Unknown `execution_hint`: [" + value + "], expected any of " + Arrays.toString(values()));
         }
 
         private final ParseField parseField;

core/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/TermsAggregatorFactory.java

@@ -41,6 +41,7 @@ import org.elasticsearch.search.aggregations.support.ValuesSourceConfig;
 import org.elasticsearch.search.internal.SearchContext;
 
 import java.io.IOException;
+import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
 
@@ -359,7 +360,7 @@ public class TermsAggregatorFactory extends ValuesSourceAggregatorFactory<Values
                     return mode;
                 }
             }
-            throw new IllegalArgumentException("Unknown `execution_hint`: [" + value + "], expected any of " + values());
+            throw new IllegalArgumentException("Unknown `execution_hint`: [" + value + "], expected any of " + Arrays.toString(values()));
         }
 
         private final ParseField parseField;