AngerTime and AngryAt cannot be set on summon

The bug

Mobs can't be summoned with AngryAt; this immediately resets their AngerTime to 0.

How to reproduce

1. Spawn in any mob where you know its UUID

   /summon pig ~ ~ ~ {UUID:[I;1,2,3,4]}

2. Summon a wolf

   /summon wolf ~ ~ ~ {AngerTime:10000,AngryAt:[I;1,2,3,4]}

   The wolf is not angry on spawn

3. Using data get shows that its AngerTime has reverted to 0 and it is missing AngryAt altogether

Note that Endermen are unreliable candidates for testing this bug, as their behavior when manually setting anger tags is inconsistent with the other neutral mobs (MC-188506).