Media attributes are not always cleared when switching apps

[zehnm]

Description

Media attributes are shown from previous app if the new app doesn't fill all media fields.

How to Reproduce

1. Start an app which provides as much media data as possible, incl seek, for example Spotify
2. Switch to an app providing very little media data. Good candidates are IP-TV apps without seek, for example TV7
3. Some media data from app is still shown, e.g. media_album, media_artist, media_position, media_position_updated_at

Expected behavior

All metadata is cleared when switching apps

Integration version

0.7.3

Additional context

Not sure if that's a general issue, or only happens if Google Cast & external metadata options are enabled.

[zehnm]

This might be an Android TV or app specific quirk:
When switching to the IP-TV app, Spotify still runs in the background and audio is mixed together from the IP-TV channel & Spotify. Android is still reporting the media data from Spotify, but the IP-TV app is reported as running app (likely because it's in the foreground)...
I continue testing with other apps. As a user I'd expect that Spotify would be stopped when another media starts playing.