Do not preserve debug console output in sys:log

This will prevent logd from ingesting it as logs in the future.

This makes use of the new feature introduced in kernel!321 (merged).

config/x86_64/desktop-contain.toml

@@ -28,7 +28,7 @@ unset VT
 path = "/usr/lib/init.d/30_console"
 data = """
 getty --contain 2
-getty --contain debug: -J
+getty --contain /scheme/debug/no-preserve -J
 """
 
 [[files]]