rpc: added configuration for yamux session (#25466)

Fixes: https://github.com/hashicorp/nomad/issues/25380

command/agent/testdata/sample1/sample1.json

@@ -18,6 +18,14 @@
   "leave_on_terminate": true,
   "log_level": "INFO",
   "region": "global",
+  "rpc": {
+    "accept_backlog": 256,
+    "keep_alive_interval": "30s",
+    "connection_write_timeout": "10s",
+    "max_stream_window_size": 262144,
+    "stream_open_timeout": "75s",
+    "stream_close_timeout": "5m"
+  },
   "server": {
     "bootstrap_expect": 3,
     "enabled": true