Explicitly declare which permissions can be granted via signature

This moves the older <allow-permissions> implementation inline with the
newer one, which requires any permission that can be granted via a
signature to explicitly add the attribute allowViaWhitelist="true".

Change-Id: Ie9f9bf6e2138075b750c58090dcd7030eff174f1
Signed-off-by: Roman Birg <roman@cyngn.com>