Convert RegistryTests to JUnit 4.

There is failure in nightly:
junit.framework.AssertionFailedError
at junit.framework.Assert.fail(Assert.java:55)
at junit.framework.Assert.assertTrue(Assert.java:22)
at junit.framework.Assert.assertNotNull(Assert.java:256)
at junit.framework.Assert.assertNotNull(Assert.java:248)
at junit.framework.TestCase.assertNotNull(TestCase.java:417)
at org.eclipse.equinox.common.tests.registry.RegistryListenerTest.testRegularOrder(RegistryListenerTest.java:88)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native
Method)
Let's have the tests modernized before looking into potential reason as
it seems to be unstable test first.

Change-Id: I1ae584c16f7c838ba82f999c501c7464118de5d6
Signed-off-by: Alexander Kurtakov <akurtako@redhat.com>
7 files changed