one thing are the list of permissions in the manifest, another thing is to ask for permissions... you only can ask for those permissions, which have been listed in the manifest
however afaik for the location sensor the permissions will be asked automatically on starting the app?
if you do not like that, you could remove the location sensor from the project, edit the manifest to add the permissions (ACCESS_FINE_LOCATION and,ACCESS_COARSE_LOCATION) manually and use the AskForPermission method to ask for those permissions before using the AvailableSSIDs method
to edit the manifest see this thread
Taifun