Add missing files to BUILD.gn am: d0ec651ac4 am: 08bb425b5e am: 67d04d939f am: 205d9ae1d3

Original change: https://android-review.googlesource.com/c/platform/system/update_engine/+/1428104

Change-Id: I7984fadde5f3910294aecdebd457b7201876f9ff