Dump ENR appear animation states

The linked bug might be caused by concurrent appear animations started
for the same row, and one of them not being finalized. Dump the states
of the appear animation to help investigate.

Bug: 356958336
Test: dumpsysui NotificationStackScrollLayout
Flag: EXEMPT changing dumps only
Change-Id: Id77ba47ecf9aae0d1d885d13f5ff937ab378591d