Checks that permission names are unique

The unqualified names or your permissions must be unique. The reason for this is that at build time, the aapt tool will generate a class named Manifest which contains a field for each of your permissions. These fields are named using your permission unqualified names (i.e. the name portion after the last dot).

If more than one permission maps to the same field name, that field will arbitrarily name just one of them.