examples: Fix egress-gateway-policy

Previously:

$ k apply -f examples/kubernetes-egress-gateway/egress-gateway-policy.yaml
The CiliumEgressGatewayPolicy "egress-sample" is invalid:
* spec.egressGateway.nodeSelector.matchLabels.egress-node:
    Invalid value: "boolean":
        spec.egressGateway.nodeSelector.matchLabels.egress-node in body must be
        of type string: "boolean"
* spec.egressGateways[0].nodeSelector.matchLabels.egress-node:
    Invalid value:
        "boolean": spec.egressGateways[0].nodeSelector.matchLabels.egress-node
        in body must be of type string: "boolean"
* spec.egressGateways[1].nodeSelector.matchLabels.egress-node-2:
    Invalid value: "boolean":
        spec.egressGateways[1].nodeSelector.matchLabels.egress-node-2 in body
        must be of type string: "boolean"
* spec.egressGateways[2].nodeSelector.matchLabels.egress-node-3:
    Invalid value: "boolean":
        spec.egressGateways[2].nodeSelector.matchLabels.egress-node-3 in body
        must be of type string: "boolean"

Fixes: 9b81aed ("pkg/egressgateway: Add documentation for multigateway")

Signed-off-by: Alexis La Goutte <alexis.lagoutte@gmail.com>
Signed-off-by: Joe Stringer <joe@cilium.io>

Author: alagoutte

examples/kubernetes-egress-gateway/egress-gateway-policy.yaml

@@ -21,7 +21,7 @@ spec:
       matchLabels:
         # The following label selects which node will act as egress gateway for
         # this policy
-        egress-node: true
+        egress-node: "true"
     # IP used to masquerade traffic leaving the cluster
     egressIP: "192.168.60.100"
     # Alternatively it is possible to:
@@ -35,24 +35,23 @@ spec:
     # In this case the first IPv4 assigned to the interface with the default
     # route will be used as egressIP
   egressGateways:
-    # It's possible to specify multiple egress gateways. In this case the source
-    # endpoints will egress traffic through one of the gateways listed below.
-    #
-    # If this field is used the contents of the egressGateway field above will
-    # be ignored.
-    # 
-    # Entries on this list have the exact same configuration options as the
-    # EgressGateway field above.
-  - egressGateway:
-    nodeSelector:
+  # It's possible to specify multiple egress gateways. In this case the source
+  # endpoints will egress traffic through one of the gateways listed below.
+  #
+  # If this field is used the contents of the egressGateway field above will
+  # be ignored.
+  #
+  # Entries on this list have the exact same configuration options as the
+  # EgressGateway field above.
+  - nodeSelector:
       matchLabels:
-        egress-node: true
+        egress-node: "true"
     egressIP: "192.168.60.100"
   - nodeSelector:
       matchLabels:
-        egress-node-2: true
+        egress-node-2: "true"
     egressIP: "192.168.60.101"
   - nodeSelector:
       matchLabels:
-        egress-node-3: true
+        egress-node-3: "true"
     egressIP: "192.168.60.102"