Update doc and vm config to use hvc0 for console

Bug: 332603752
Test: connect to ferrochrome console
Change-Id: Iee426f62d9918754e7cf12fddba286e33e20a5e2
diff --git a/ferrochrome_app/vm_config.json.template b/ferrochrome_app/vm_config.json.template
index cb968ec..6e1992f 100644
--- a/ferrochrome_app/vm_config.json.template
+++ b/ferrochrome_app/vm_config.json.template
@@ -33,5 +33,5 @@
         "backend": "virglrenderer",
         "context_types": ["virgl2"]
     },
-    "console_input_device": "ttyS0"
+    "console_input_device": "hvc0"
 }