Remove t() from test assertion messages

We're in the midst of a big clean-up effort in Core 7/8 to remove t() from test assertion messages:
#500866: [META] remove t() from assert message
#1457320: Document that t() should not be used for assertion message texts and groups

It seems that at least some of the test assertions in the Examples project still have t() on assert messages, and in order to be good examples, they shouldn't.
http://drupal.org/simpletest-tutorial-drupal7#t

For example, in action_example.test:

    $this->assertTrue($normal_user->status, t('Normal user status has been set to unblocked'));

should be:

    $this->assertTrue($normal_user->status, 'Normal user status has been set to unblocked');

There may not be too many problems of this nature... for example, node_example.test looks to be clean... but there are at least some.