samples: hello_world: Change to full logging

Change this app to use full logging in Zephyr.  This requires a larger
stack, and at least for now, we disable the RTT logging, as the logging
seems to get confused if more than one back end is present.

Signed-off-by: David Brown <[email protected]>

Author: d3zd3z

samples/hello_world/prj.conf

@@ -1,7 +1,12 @@
 # Copyright (c) 2024 Linaro LTD
 # SPDX-License-Identifier: Apache-2.0
 
+# The default 1k stack isn't large enough for rust string formatting with logging.
+CONFIG_MAIN_STACK_SIZE=4096
+
 CONFIG_RUST=y
 
-# CONFIG_RUST_ALLOC=y
-# CONFIG_LOG=y
+CONFIG_RUST_ALLOC=y
+CONFIG_LOG=y
+
+CONFIG_LOG_BACKEND_RTT=n