Allow the payload running in Microdroid to interact with kmsg

When debuggable property is set, allow the payload running in the VM to
show messages to kmsg.

Depends on :
https://android-review.git.corp.google.com/c/platform/system/sepolicy/+/3346847

Test: run the Empty Payload as per the AVF doceumentation and make sure
that we see the Hello Microdroid log.
Bug: 378479069
Change-Id: I662437eb32f862102606b4d842632f884e27e769
Signed-off-by: Sebastian Ene <sebastianene@google.com>
diff --git a/guest/microdroid_manager/src/main.rs b/guest/microdroid_manager/src/main.rs
index fa089fa..c5fa864 100644
--- a/guest/microdroid_manager/src/main.rs
+++ b/guest/microdroid_manager/src/main.rs
@@ -669,7 +669,9 @@
         });
     }
 
-    command.stdin(Stdio::null()).stdout(Stdio::null()).stderr(Stdio::null());
+    if !is_debuggable()? {
+        command.stdin(Stdio::null()).stdout(Stdio::null()).stderr(Stdio::null());
+    }
 
     info!("notifying payload started");
     service.notifyPayloadStarted()?;