Partial revert f7be7e6a. Change commons abbrvThreshold back to 160.

The abbrvThreshold of commons as a foreign repo must be kept in
sync with the local abbrvThreshold at commons, or images with a
file name length between the two values will break.

The change from 160 to 140 appears to have been accidental.

Bug: 72389
Change-Id: Id7f9b36b283ed0cf92d7bd3afa607d240ca35f5f