So last week we we're getting our app refused from the Nook store as the line <uses-permission android:name="android.permission.VIBRATE" /> was being generated by Unity in the androidManifest.xml and vibrate is not allowed on the nook (or Kindle either).
Turns out just having DeviceVibrate.cs in the actions folder causes this, you don't have to have used it.
So delete it and Unity automatically removes it on build. You can check in the stagingArea folder in your Main project folder.
Hope this helps.