Bringing back camera-undo/redo buttons by popular demand.

Brings back camera undo/redo buttons that were removed by
efe5a43c5bf940242ad0f53f79ec323683fecfad.

Change-Id: I265378a97439b74e4812dccc8f84d4eaad0dadf5
Merge topic 'bring_back_camera_undo' into next

1cf7e0c Bringing back camera-undo/redo buttons by popular demand.