Add API coverage for javax.xml.validation.{Validator,ValidatorHandler}

API list:
 * javax.xml.validation.TypeInfoProvider.TypeInfoProvider()
 * javax.xml.validation.Validator.Validator()
 * javax.xml.validation.Validator.getFeature(java.lang.String)
 * javax.xml.validation.Validator.getProperty(java.lang.String)
 * javax.xml.validation.Validator.setFeature(java.lang.String, boolean)
 * javax.xml.validation.Validator.setProperty(java.lang.String, java.lang.Object)
 * javax.xml.validation.Validator.validate(javax.xml.transform.Source)
 * javax.xml.validation.ValidatorHandler.ValidatorHandler()
 * javax.xml.validation.ValidatorHandler.getFeature(java.lang.String)
 * javax.xml.validation.ValidatorHandler.getProperty(java.lang.String)
 * javax.xml.validation.ValidatorHandler.setFeature(java.lang.String, boolean)
 * javax.xml.validation.ValidatorHandler.setProperty(java.lang.String, java.lang.Object)

Bug: 200274301
Test: atest CtsLibcoreTestCases:libcore.javax.xml.validation.{\
            ValidatorTest,ValidatorHandlerTest}
Merged-In: Ibe6d30e9f36a44eb8989444d4b2740faed99692c
Change-Id: Ibe6d30e9f36a44eb8989444d4b2740faed99692c
2 files changed