Disallow reflection access to AdapterView#mDataChanged after P.

I talked to the biggest 3p user of this API and they are resilient
to this change.  Moving forward, our advice to developers is to
use RecyclerView.

Test: N/A
Change-Id: I8de647b10ed06f1f0f4b10865fb88ac0bcc10608
Fixes: 123768524