As per my knowledge (maybe someone corrects me) - this permission was needed for proper communication between AIR and device system, but there was not need to have it explicitly set in app.xml. AIR application, when installing, simply asked also for this permission even if not set it in app.xml. I think, you can remove it without any noticeable effect, if your app does not need it to run. (mine app also does not need it, and I do not have in XML). But better test it before publishing.