Android: can I protect an app portion with a signature-level permission that is defined in another app with a different signature?

Question

Let's assume that the Android app App1 declares the following permission:

<permission android:name="unipd.elia.delta.DELTA_SERVICE_MANAGER"
    android:description="@string/startDeltaServicePermission_description"
    android:protectionLevel="signature"/>

Obviously, this declaration means that only other apps signed with the same key as App1 can use (acquire) that permission.

However, my question is this: can another app App2, which is signed with a different key than App1, protect a portion of itself with that permission? In other words, can App2 do this:

<service android:name=".DeltaLoggingService" android:process=":remote" android:exported="true"
        android:permission="unipd.elia.delta.DELTA_SERVICE_MANAGER" />

even if App2 was not signed with the same key as App1?

EDIT: In case ayone is interested, the real-world scenario is this: App1 can interact with other apps that act as plugins for it, and I want to allow third parties to develop new plugins which can be used by App1. However, I don't want apps other than App1 (or any app not developed by me) to interact with such plugins.

Answer 1

Well, while waiting for the answer I had time to test myself and yes, it works.