OCPBUGS-49441: Use different certificates for gRPC interoperability test routes

Before this change the gRPC routes were using the same certificate which
prevented the usage of ALPN to avoid the connection coalescing.
This commit introduces different certificates for edge and reencrypt
routes.

Author: alebedev87

test/extended/router/grpc-interop.go

@@ -187,6 +187,15 @@ var _ = g.Describe("[sig-network-edge][Conformance][Area:Networking][Feature:Rou
 			pemCrt, err := certgen.MarshalCertToPEMString(tlsCrtData)
 			o.Expect(err).NotTo(o.HaveOccurred())
 
+			_, tlsCrt2Data, tlsPrivateKey2, err := certgen.GenerateKeyPair("Root CA", notBefore, notAfter)
+			o.Expect(err).NotTo(o.HaveOccurred())
+
+			derKey2, err := certgen.MarshalPrivateKeyToDERFormat(tlsPrivateKey2)
+			o.Expect(err).NotTo(o.HaveOccurred())
+
+			pemCrt2, err := certgen.MarshalCertToPEMString(tlsCrt2Data)
+			o.Expect(err).NotTo(o.HaveOccurred())
+
 			shardFQDN := oc.Namespace() + "." + defaultDomain
 
 			g.By("Creating routes to test for gRPC interoperability")
@@ -253,8 +262,8 @@ var _ = g.Describe("[sig-network-edge][Conformance][Area:Networking][Feature:Rou
 						TLS: &routev1.TLSConfig{
 							Termination:                   routev1.TLSTerminationReencrypt,
 							InsecureEdgeTerminationPolicy: routev1.InsecureEdgeTerminationPolicyRedirect,
-							Key:                           derKey,
-							Certificate:                   pemCrt,
+							Key:                           derKey2,
+							Certificate:                   pemCrt2,
 						},
 						To: routev1.RouteTargetReference{
 							Kind:   "Service",