Add docs for example of health check gRPC success codes. (#2700)

aws-load-balancer-controller currently supports gRPC target group and ALB can checks grpc-status with health check.
https://github.com/kubernetes-sigs/aws-load-balancer-controller/blob/9c79e45dd4b8cf94b97a1c6737bf1d47306460d0/pkg/ingress/model_build_target_group.go#L386-L394

docs/guide/ingress/annotations.md

@@ -631,7 +631,7 @@ Health check on target groups can be controlled with following annotations:
         alb.ingress.kubernetes.io/healthcheck-timeout-seconds: '8'
         ```
 
-- <a name="success-codes">`alb.ingress.kubernetes.io/success-codes`</a> specifies the HTTP status code that should be expected when doing health checks against the specified health check path.
+- <a name="success-codes">`alb.ingress.kubernetes.io/success-codes`</a> specifies the HTTP or gRPC status code that should be expected when doing health checks against the specified health check path.
 
     !!!example
         - use single value
@@ -646,6 +646,18 @@ Health check on target groups can be controlled with following annotations:
             ```
             alb.ingress.kubernetes.io/success-codes: 200-300
             ```
+        - use gRPC single value
+            ```
+            alb.ingress.kubernetes.io/success-codes: '0'
+            ```
+        - use gRPC multiple value
+            ```
+            alb.ingress.kubernetes.io/success-codes: 0,1
+            ```
+        - use gRPC range of value
+            ```
+            alb.ingress.kubernetes.io/success-codes: 0-5
+            ```
 
 - <a name="healthy-threshold-count">`alb.ingress.kubernetes.io/healthy-threshold-count`</a> specifies the consecutive health checks successes required before considering an unhealthy target healthy.