[BUG] Fix org.opensearch.common.xcontent.XContentParserTests.testString flaky test (opensearch-project#13164)

Signed-off-by: Andriy Redko <andriy.redko@aiven.io>

Author: reta

libs/x-content/src/test/java/org/opensearch/common/xcontent/XContentParserTests.java

@@ -85,8 +85,8 @@ public class XContentParserTests extends OpenSearchTestCase {
         () -> randomAlphaOfLengthBetween(1, SmileXContent.DEFAULT_MAX_STRING_LEN),
         /* YAML parser limitation */
         XContentType.YAML,
-        /* use 75% of the limit, difficult to get the exact size of the content right */
-        () -> randomRealisticUnicodeOfCodepointLengthBetween(1, (int) (YamlXContent.DEFAULT_CODEPOINT_LIMIT * 0.75))
+        /* use 50% of the limit, difficult to get the exact size of the content right */
+        () -> randomRealisticUnicodeOfCodepointLengthBetween(1, (int) (YamlXContent.DEFAULT_CODEPOINT_LIMIT * 0.50))
     );
 
     private static final Map<XContentType, Supplier<String>> OFF_LIMIT_GENERATORS = Map.of(