Revert "ui: Refactor stable ID generation for GPU virtual displays"

This reverts commit 78c90af2224b43467d854e356492527db0f8eb70.

Reason for revert: Causes assert for certain GPU virtual display Ids in VirtualDisplaySurface.cpp (https://paste.googleplex.com/6474098414977024)

Change-Id: I743312bbab4fd9903e069c3ed4710f9d7901be8d
5 files changed