Add metrics to update check code
Created by: daxmc99
This adds metrics to the update check code and can be used to decide which functions require some degree of refactoring.
Addresses https://github.com/sourcegraph/sourcegraph/issues/9867
Note, I don't think this code should remain here long term. There is a high degree of cardinality here and this should only be used to determine what parts of updatecheck need refactoring