add appprovider frontend route

deployments/examples/ocis_wopi/config/ocis/proxy-config.json

@@ -32,6 +32,10 @@
           "endpoint": "/ocs/v[12].php/cloud/(users?|groups)",
           "backend": "http://localhost:9110"
         },
+        {
+          "endpoint": "/app/",
+          "backend": "http://localhost:9140"
+        },
         {
           "endpoint": "/ocs/",
           "backend": "http://localhost:9140"

proxy/pkg/proxy/proxy.go

@@ -295,6 +295,10 @@ func defaultPolicies() []config.Policy {
 					Endpoint: "/ocs/v[12].php/cloud/(users?|groups)", // we have `user`, `users` and `groups` in ocis-ocs
 					Backend:  "http://localhost:9110",
 				},
+				{
+					Endpoint: "/app/",
+					Backend:  "http://localhost:9140",
+				},
 				{
 					Endpoint: "/ocs/",
 					Backend:  "http://localhost:9140",