Remove unused native implementation of Object.wait()

As part of the process of verifying Java files against 8u121-b13 the
Object.wait() method has been changed from a native method to a pure
Java implementation. This removes the unused native implementation
method and the supporting method in mirror::Object.

Updated the 911-get-stack-trace test to handle the two extra stack
elements added by this change.

Bug: 74379469
Test: make checkbuild, flash
Change-Id: Ifbc4612f7d949416d8c703628fa8cafaa296c350