Update Verkehrsverbund Berlin-Brandenburg feed name to include VBB

[isabelle-dr]

Problem: Verkehrsverbund Berlin-Brandenburg is often also called VBB.
Additionally, it seems like we have a typo in the Realtime feed name: "Verkehrsverbind" instead of "Verkehrsverbund".

Feeds:

• https://mobilitydatabase.org/feeds/gtfs_rt/mdb-2378
• https://mobilitydatabase.org/feeds/gtfs/mdb-782

Task:

• Update name of both feeds to Verkehrsverbund Berlin-Brandenburg (VBB)
  Similar to the name of this feed.