Move PreparedModelCallback to runtime/test -- 2/2

This is a revert of I9eade321, which is a revert of Ifa554e22a.

PreparedModelCallback is no longer used by the runtime.

Bug: 170289677
Test: NNT_static
Change-Id: I5bacb0880d789c1135ab54bf3d001b08de1d6edc
14 files changed