Add support for new UnifiedPush specifications, and fallback to the previous ones.

[p1gp1g]

The specifications where updated recently: https://codeberg.org/UnifiedPush/specifications/pulls/1

Mainly it adds

• Add the capacity to set a default distributor per system (with the Link Activity)
• VAPID support
• Ability to raise the connected app to the foreground
• Reduce ability to impersonate another app to create a topic, used to rate limit number of registrations per user
• Clarify some stuff, like the reasons why a registration fail

[redstrate]

Note that in order for BRING_TO_FOREGROUND to work in modern Android without being blocked by PackageManager, you need this in the AndroidManifests.xml:

    <queries>
        <intent>
            <action android:name="org.unifiedpush.android.distributor.RAISE_TO_FOREGROUND" />
        </intent>
    </queries>

Otherwise the receiving app is never visible, and it will never end up calling the Service :)

[p1gp1g]

Indeed, that explain why it failed sometimes. Surprisingly:

• It don't always fail, maybe it works after the targettted app sends an intent to ntfy ?
• It works when filtering other actions, for instance the following. This is why I missed it, I didn't have to do it for NextPush

    <queries>
        <intent>
            <action android:name="org.unifiedpush.android.connector.NEW_ENDPOINT" />
        </intent>
    </queries>

[redstrate]

It don't always fail, maybe it works after the targettted app sends an intent to ntfy ?

In my case it was blocking actions from ntfy to the app, I'm not sure exactly why this specific intent was blocked while the others were fine. Unfortunately PackageManager doesn't explain itself when it blocks :D