[Minimal HUN] Use Heads Up Height for Minimal HUN

Fixes: 383472650
Fixes: 377441373
Test: Post minimal HUN notification and observe dismiss animation. HUN shouldn't jump to expanded view during dismiss.
Post minimal HUN in immerse mode, wait for dismiss and pull the shade. There shouldn't be any jump on the shade.
Flag: android.app.compact_heads_up_notification

Change-Id: I193ffeea56858091e740457c3951b63e3000dff7