The Bug

Renaming a vindicator that has been named 'Johnny' does not reset its behavior of attacking most mobs. It would be expected that vindicators that were renamed from 'Johnny' to another name would stop their behavior due to that name.

This can be fixed by changing the Johnny tag from 1b to 0b whenever its name changes.

How to Reproduce

1. Rename two nametags - one to be Johnny and the other one to be any name other than Johnny.
2. Make a setup as shown in the image below; two holes with a block on top to fit two different two-block tall mobs.
3. Spawn a vindicator in one of the holes and name it Johnny using the nametag. Look at the vindicator and press F3 + I. Paste it in a Notepad and confirm that the Johnny tag is set to 1b.
4. Spawn another mob like a creeper in the other hole, and note how the vindicator tries to attack it.
5. Now rename the vindicator to the other name, and note how it still tries to attack the mob. Press F3 + I again and paste it into a Notepad. Note how the Johnny tag is still 1b.