Bug 469760 - [otdre] team activation for indirect subtype of Runnable

From https://bugs.eclipse.org/469760 :

Test org.eclipse.objectteams.otdt.tests.otjld.teamactivation.ExplicitTeamActivation.test5215_explicitActivationForAllThreads1a() still fails under OTDRE:

We don't find the Runnable indirect supertype