[Rest Api Compatibility] Return adjust_pure_negative values (#75182)

the adjust_pure_negative value used to be always present in to_xcontent
response, but it was changed in #49543 to only serialise this field when
the value is false

relates #51816

Author: pgomulka

rest-api-spec/build.gradle

@@ -107,7 +107,6 @@ tasks.named("yamlRestCompatTest").configure {
     'search/260_parameter_validation/test size=-1 is deprecated', //size=-1 change
     'search/310_match_bool_prefix/multi_match multiple fields with cutoff_frequency throws exception', //cutoff_frequency
     'search/340_type_query/type query', // type_query - probably should behave like match_all
-    'search_shards/10_basic/Search shards aliases with and without filters',
    ] + v7compatibilityNotSupportedTests())
     .join(',')
 }

server/src/main/java/org/elasticsearch/index/query/BoolQueryBuilder.java

@@ -21,6 +21,7 @@
 import org.elasticsearch.common.xcontent.ObjectParser;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentParser;
+import org.elasticsearch.core.RestApiVersion;
 
 import java.io.IOException;
 import java.util.ArrayList;
@@ -251,7 +252,9 @@ protected void doXContent(XContentBuilder builder, Params params) throws IOExcep
         doXArrayContent(FILTER, filterClauses, builder, params);
         doXArrayContent(MUST_NOT, mustNotClauses, builder, params);
         doXArrayContent(SHOULD, shouldClauses, builder, params);
-        if (adjustPureNegative != ADJUST_PURE_NEGATIVE_DEFAULT) {
+        if (builder.getRestApiVersion() == RestApiVersion.V_7) {
+            builder.field(ADJUST_PURE_NEGATIVE.getPreferredName(), adjustPureNegative);
+        } else if (adjustPureNegative != ADJUST_PURE_NEGATIVE_DEFAULT) {
             builder.field(ADJUST_PURE_NEGATIVE.getPreferredName(), adjustPureNegative);
         }
         if (minimumShouldMatch != null) {