testHlrcFromXContent() should respect assertToXContentEquivalence()

Tests can override assertToXContentEquivalence() in case their xcontent
cannot be directly compared (e.g. due to insertion order in maps
affecting the xcontent ordering).  But the `testHlrcFromXContent` test
hardcoded the equivalence test to `true` instead of consulting
`assertToXContentEquivalence()`

Fixes elastic#36034
Backport of elastic#38232

Author: polyfractal

x-pack/plugin/core/src/test/java/org/elasticsearch/protocol/AbstractHlrcXContentTestCase.java

@@ -21,7 +21,7 @@ public final void testHlrcFromXContent() throws IOException {
         AbstractXContentTestCase.testFromXContent(NUMBER_OF_TEST_RUNS, this::createTestInstance, supportsUnknownFields(),
             getShuffleFieldsExceptions(), getRandomFieldsExcludeFilter(), this::createParser,
             p -> convertHlrcToInternal(doHlrcParseInstance(p)),
-            this::assertEqualInstances, true, getToXContentParams());
+            this::assertEqualInstances, assertToXContentEquivalence(), getToXContentParams());
     }
 
     /**