[TESTBUG]两个dcmd/gc用例使用UseSerialGC选项运行失败

job：https://tone.aliyun-inc.com/ws/xesljfzh/test_result/257346?tab=3

test/hotspot/jtreg/serviceability/dcmd/gc/HeapDumpParallelTest.java

java.lang.RuntimeException: 'Dump heap objects in parallel' found in stdout 

    at jdk.test.lib.process.OutputAnalyzer.shouldNotContain(OutputAnalyzer.java:209)
    at HeapDumpParallelTest.checkAndVerify(HeapDumpParallelTest.java:69)
    at HeapDumpParallelTest.test(HeapDumpParallelTest.java:132)
    at HeapDumpParallelTest.main(HeapDumpParallelTest.java:118)

test/hotspot/jtreg/serviceability/dcmd/gc/HeapDumpCompressedTest.java#id0

Error occurred during initialization of VM
Multiple garbage collectors selected

dragonwell-project / dragonwell11

[TESTBUG]两个dcmd/gc用例使用UseSerialGC选项运行失败 #740