android instrumentation test for home button interaction

HomeAndRelaunch.java

    Intent home = new Intent();
    home.setAction(Intent.ACTION_MAIN);
    home.addCategory(Intent.CATEGORY_HOME);
    home.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

    Intent relaunch = new Intent(rule.getActivity(), rule.getActivity().getClass());
    relaunch.addFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);

    InstrumentationRegistry.getTargetContext().startActivity(home);
    Thread.sleep(500); // XXX
    rule.getActivity().startActivity(relaunch);