[Notif redesign] Fix group header motion on tap

A slightly different approach after
I2327de4dd1a14f40fae0d121de653516e3df55cb had to be reverted.

We had previously made this motion more gradual during the dragging
gesture in I21ef172ba5ad14404e1c863c209a35bada3790d4, but that didn't
fix the motion when the group was expanded via tapping, since that has
to be done in startAnimationToState instead of relying on updateState.

This allows us to remove the call fron NSSL that was directly updating
the alignment without any transition.

Fix: 402745695
Test: manual
Flag: android.app.notifications_redesign_templates
Change-Id: I55205f3d6e58858a6328aa5d54a6126e2e32232e