Fix a few bugs in net up --kubernetes (#4516)

## Motivation

Some of the configs were wrong, as well as the port forwarding, making
notifications stop working and 3 of the tests fail.

## Proposal

Do the required fixes (wrong address, port forwarding, etc). Fixes
#4494

## Test Plan

Started a local network with `net up --kubernetes`, ran e2e tests
against it, they all pass.

## Release Plan

- Nothing to do / These changes follow the usual release cycle.

Author: ndr-ds

configuration/compose/validator.toml

@@ -15,7 +15,6 @@ Grpc = "ClearText"
 host = "proxy"
 private_port = 20100
 public_port = 19100
-metrics_host = "proxy"
 metrics_port = 21100
 
 [[shards]]

linera-service/src/cli_wrappers/local_kubernetes_net.rs

@@ -382,7 +382,7 @@ impl LocalKubernetesNet {
                 Grpc = "ClearText"
 
                 [[proxies]]
-                host = "proxy-0.default.svc.cluster.local"
+                host = "proxy-0.proxy-internal.default.svc.cluster.local"
                 public_port = {port}
                 private_port = {internal_port}
                 metrics_port = {metrics_port}
@@ -495,7 +495,7 @@ impl LocalKubernetesNet {
                 let local_port = 19100 + i;
                 kubectl_instance.port_forward(
                     proxy_service,
-                    &format!("{local_port}:{local_port}"),
+                    &format!("{local_port}:19100"),
                     cluster_id,
                 )?;
 

linera-service/src/cli_wrappers/local_net.rs

@@ -514,7 +514,6 @@ impl LocalNet {
                 host = "{internal_host}"
                 public_port = {public_port}
                 private_port = {internal_port}
-                metrics_host = "{external_host}"
                 metrics_port = {metrics_port}
                 "#
             ));

linera-service/src/server.rs

@@ -618,7 +618,6 @@ mod test {
             host = "proxy"
             public_port = 20100
             private_port = 20200
-            metrics_host = "proxy"
             metrics_port = 21100
 
             [[shards]]