The Wikipedia Android app shows notifications from various wikis. In the notification item menu, the messages about the notification itself are shown in the language of that wiki, but the "Mark as read" message at the bottom of the menu is shown in the language of the phone. See the examples.

For example, I use the phone in Hebrew, but I receive notifications from wikis in Hebrew, English, Catalan, and other languages. Here, "View changes", "View page", and "Stop showing notifications like this" are shown in Catalan, but "Mark as read" in the end is in Hebrew:

And here is the same issue, but with English:

I guess that the reason for this is that "Mark as read" comes from the code of the app itself, but the notification-specific messages come from the wikis.

It would more consistent and generally much nicer and less weird if the whole menu was in the same language. So either show the notifications in the language of the app, or show all the items in the language of the wiki (if you cannot load it from the app's code, you can perhaps pull the message echo-notification-markasread from the wiki).