flush console to output file: restored for cases with short output (IDEA-161123)

java/execution/impl/src/com/intellij/execution/JavaTestFrameworkRunnableState.java

@@ -161,6 +161,7 @@ public abstract class JavaTestFrameworkRunnableState<T extends
       @Override
       public void processTerminated(ProcessEvent event) {
         Runnable runnable = () -> {
+          root.flushOutputFile();
           deleteTempFiles();
           clear();
         };