According to Android development documentation (see http://developer.android.com/training/in-app-billing/test-iab-app.html ) there is a field in the developer console settings for Android apps where IAB test-enabled gmail accounts go. There is also a combo box to set the license test answer. Some choices are available, among which "RESPOND_NORMALLY" or "LICENSED". So, it seems that those gmail accounts will not be able to test the "real" IAB workflow, because the answer is chosen by me. Am I wrong? Is "RESPOND_NORMALLY" the choice to test the normal IAB workflow?
If you are testing the In App Purchase workflow, there is no difference on which value you set as license test answer, since this value is used only for testing Licensed applications (i.e. for paying apps). You can leave both RESPOND_NORMALLY or LICENSED (I personally left LICENSED).