Shell: Fix issue with koush SuperUser Daemon state
When adding non-binary commands to the shell using koush SuperUser Daemon (Android 4.3 SELinux fix), it some times does not return any output from the command executed above. So we change Shell to use echo to print the EOL token and the result code. This will produce an issue if the shell used on the device cannot find the echo command. Most shells does provide an internal echo command, but if there should be a shell that does not, and the echo command is not to find in one of the bin folders, this will not end well.