Measure Gitaly migration sites against original
Measure Gitaly migration sites against original

We were missing data for Gitaly migration call sites against the
original implementation. This commit adds a histogram with a flag
telling us if gitaly received the call or the original implementation
did.

stoplightio/gitlabhq,axilleas/gitlabhq,axilleas/gitlabhq,jirutka/gitlabhq,stoplightio/gitlabhq,mmkassem/gitlabhq,iiet/iiet-git,mmkassem/gitlabhq,axilleas/gitlabhq,iiet/iiet-git,dreampet/gitlab,stoplightio/gitlabhq,jirutka/gitlabhq,iiet/iiet-git,dreampet/gitlab,iiet/iiet-git,jirutka/gitlabhq,dreampet/gitlab,jirutka/gitlabhq,mmkassem/gitlabhq,mmkassem/gitlabhq,axilleas/gitlabhq,dreampet/gitlab,stoplightio/gitlabhq