Make liveness and readiness probe timeouts configurable
From https://gitlab.com/gitlab-org/quality/team-tasks/issues/212
Heavy load was causing execution times on liveness and readiness probes to take longer than expected, and timeout. Which lead to deployments not completing. It may have been fine to make the timeouts longer, and deploys would complete.
We're using default times in some cases (i.e. unicorn readinessProbe), and hard coding values in others (i.e. gitaly, unicorn livenessProbe). We should make these options configurable, with sane defaults.
It may be worth considering a global timeout value that users can set, as well as individual values for each piece of the chart.
We do not appear (based on values.yml and doc/charts/globals.md) to offer this option currently.