Fix test for terms on boolean (#83602)

The test for boolean terms on multi-valued fields would sometimes
generate many documents that all had an empty array of boolean fields.
The test would then fail because we'd never actually map the boolean
field at all and we'd get an "unmapped" terms agg result. This fixes the
test to always generate at least one boolean.

Closes #83488

server/src/internalClusterTest/java/org/elasticsearch/search/aggregations/bucket/BooleanTermsIT.java

@@ -18,6 +18,7 @@ import org.elasticsearch.test.ESIntegTestCase;
 import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.assertSearchResponse;
 import static org.elasticsearch.xcontent.XContentFactory.jsonBuilder;
 import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.hasSize;
 import static org.hamcrest.core.IsNull.notNullValue;
 
 @ESIntegTestCase.SuiteScopeTestCase
@@ -43,7 +44,7 @@ public class BooleanTermsIT extends ESIntegTestCase {
                 numSingleFalses++;
             }
             final boolean[] multiValue;
-            switch (randomInt(3)) {
+            switch (between(i == 0 ? 1 : 0, 3)) { // Make sure the first document has at least one value
                 case 0 -> multiValue = new boolean[0];
                 case 1 -> {
                     numMultiFalses++;
@@ -105,7 +106,6 @@ public class BooleanTermsIT extends ESIntegTestCase {
         }
     }
 
-    @AwaitsFix(bugUrl = "https://github.com/elastic/elasticsearch/issues/83488")
     public void testMultiValueField() throws Exception {
         SearchResponse response = client().prepareSearch("idx")
             .addAggregation(
@@ -119,7 +119,7 @@ public class BooleanTermsIT extends ESIntegTestCase {
         assertThat(terms, notNullValue());
         assertThat(terms.getName(), equalTo("terms"));
         final int bucketCount = numMultiFalses > 0 && numMultiTrues > 0 ? 2 : numMultiFalses + numMultiTrues > 0 ? 1 : 0;
-        assertThat(terms.getBuckets().size(), equalTo(bucketCount));
+        assertThat(terms.getBuckets(), hasSize(bucketCount));
 
         LongTerms.Bucket bucket = terms.getBucketByKey("false");
         if (numMultiFalses == 0) {