add gatekeeper_ prefix to metrics (#1598)
add gatekeeper_ prefix to metrics (#1598)

Signed-off-by: Sertac Ozercan <a438f3f0cd2281981c98ef2897c2214832094874@gmail.com>
open-policy-agent/gatekeeper,open-policy-agent/gatekeeper,open-policy-agent/gatekeeper,open-policy-agent/gatekeeper,open-policy-agent/gatekeeper