Add support of setConfigFailurePolicy

[juherr]

Related issue: gradle/gradle#19960

TestNG 7.x removed the TestNG#setConfigFailurePolicy(String) method in favor of TestNG#setConfigFailurePolicy(org.testng.xml.XmlSuite$FailurePolicy) (an enum argument).

Older (pre-5.12) TestNG libraries did not have this method at all