Add one more virtio-console device

To be in sync with Cuttlefish, have three virtio-console devices
(previously two) in Microdroid.

/dev/hvc0 is used as the kernel console where kmsg is redirected to
/dev/hvc1 is a new one and is used as the userspace console (set via
androidboot.console). This currently is not used; the backend is a sink.
/dev/hvc2 is used for logcat output

Bug: 200914564
Test: run MicrodroidDemoApp
Change-Id: Ib51be683cc2f8e19e09ae7a6b5707a196eb93ac5
diff --git a/microdroid/ueventd.rc b/microdroid/ueventd.rc
index 85f2f9d..037b8fc 100644
--- a/microdroid/ueventd.rc
+++ b/microdroid/ueventd.rc
@@ -26,4 +26,4 @@
 /dev/tty0                 0660   root       system
 
 # Virtual console for logcat
-/dev/hvc1                 0660   logd       logd
+/dev/hvc2                 0660   logd       logd