logging: backend inconsistency with console and shell

[pabigot]

If you have both a console and a shell, the log messages go to the shell UART rather than the console.

If you have both CONFIG_SHELL_LOG_BACKEND=y and CONFIG_LOG_BACKEND_UART=y set the log messages go only to the console, though they are both listed as enabled back-ends in the shell.

[github-actions]

This issue has been marked as stale because it has been open (more than) 60 days with no activity. Remove the stale label or add a comment saying that you would like to have the label removed otherwise this issue will automatically be closed in 14 days. Note, that you can always re-open a closed issue at any time.

[github-actions]

This issue has been marked as stale because it has been open (more than) 60 days with no activity. Remove the stale label or add a comment saying that you would like to have the label removed otherwise this issue will automatically be closed in 14 days. Note, that you can always re-open a closed issue at any time.