There are some test cases in ICU4J utilizing JUnitParamsRunner. All of these test cases are failing when you run ICU4J plugin unit test case as JUnit plug-in Test.
I did some investigation whether if we can include external jar in plugin unit test without packaging the jar as plug-in, but I still cannot find the solution yet.
After setting up some classpath, com.ibm.icu.dev.test.serializable.CompatibilityTest still fails because generateClassList does not support "resourcebundle:" protocol. So it cannot get a list of test data files. I did not investigate other test failures yet.