Remove outdated constraint documentation.
Remove outdated constraint documentation.

Reviewed at https://reviews.apache.org/r/41155/

crashlytics/aurora,medallia/aurora,rdelval/aurora,thinker0/aurora,apache/aurora,thinker0/aurora,medallia/aurora,crashlytics/aurora,protochron/aurora,protochron/aurora,apache/aurora,medallia/aurora,protochron/aurora,crashlytics/aurora,rdelval/aurora,thinker0/aurora,protochron/aurora,protochron/aurora,thinker0/aurora,rdelval/aurora,medallia/aurora,thinker0/aurora,thinker0/aurora,medallia/aurora,crashlytics/aurora,apache/aurora,apache/aurora,medallia/aurora,rdelval/aurora,crashlytics/aurora,protochron/aurora,rdelval/aurora,apache/aurora,crashlytics/aurora,rdelval/aurora,apache/aurora