ipatests: mark known failures as xfail

Commit 5dbcc1a9d3 marked
the base class method test_replica0_with_ca_kra_dns_install
as known failure, but this does not work with inherited
classes. The child class methods need to be marked
themselves as known failures with @pytest.mark.xfail

Furthermore, TestInstallWithCA_KRA2 and TestInstallWithCA_KRA_DNS2
tests should succeed because the master is installed with KRA
(issue 7651 is related to replica install with --setup-kra
when it is the first KRA instance).

Related to https://pagure.io/freeipa/issue/7651

Reviewed-By: Rob Crittenden <rcritten@redhat.com>

ipatests/test_integration/test_installation.py

@@ -104,7 +104,6 @@ class InstallTestBase2(IntegrationTest):
     def install(cls, mh):
         tasks.install_master(cls.master, setup_dns=False)
 
-    @pytest.mark.xfail(reason='Ticket 7651', strict=True)
     def test_replica0_with_ca_kra_dns_install(self):
         tasks.install_replica(self.master, self.replicas[0], setup_ca=True,
                               setup_kra=True, setup_dns=True)
@@ -185,6 +184,7 @@ class TestInstallWithCA2(InstallTestBase2):
 
     @pytest.mark.skipif(config.domain_level == DOMAIN_LEVEL_0,
                         reason='does not work on DOMAIN_LEVEL_0 by design')
+    @pytest.mark.xfail(reason='Ticket 7651', strict=True)
     def test_replica0_with_ca_kra_dns_install(self):
         super(TestInstallWithCA2, self).test_replica0_with_ca_kra_dns_install()
 
@@ -247,6 +247,7 @@ class TestInstallWithCA_DNS2(InstallTestBase2):
 
     @pytest.mark.skipif(config.domain_level == DOMAIN_LEVEL_0,
                         reason='does not work on DOMAIN_LEVEL_0 by design')
+    @pytest.mark.xfail(reason='Ticket 7651', strict=True)
     def test_replica0_with_ca_kra_dns_install(self):
         super(
             TestInstallWithCA_DNS2, self