Certain controllers (e.g. Doorkeeper::TokensController) don't expose the
method "request_format". This commit changes
Gitlab::Metrics::WebTransaction so we don't rely on this method, instead
using the underlying code this method uses.
Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/46412
The method "content_type" on a controller does not always return the
correct content type. On the other hand, the method "request_format"
does _and_ immediately returns a Symbol (e.g. :json) instead of a
mime-type name (e.g. application/json). With these changes metrics
should again report their action names correctly.
Fixes https://gitlab.com/gitlab-com/infrastructure/issues/3499
