istio: register init push context metric (#40049)
istio: register init push context metric (#40049)

Change-Id: I61825036af32dfb5efc890606708594dd687780c
Reviewed-on: https://gerrit.musta.ch/c/public/istio/+/3310
Reviewed-by: Weibo He <d4e8291c3dbcb0f3ba5830898652c1c12ab9fa13@airbnb.com>
istio/istio,istio/istio,istio/istio,istio/istio,istio/istio