[launch]: Fix the game-executable-check command to handle the error case
[launch]: Fix the game-executable-check command to handle the error case

In the prior CL to add this check to restore the binary-missing error,
the ssh command's error case was not checked, which caused the command
to fail when the executable was not present and unexpectedly throw. This
CL handles that failure case.

GitOrigin-RevId: 9529400219d67d50e52a8c406a8d41e8416205ad

googlestadia/vsi-lldb,googlestadia/vsi-lldb,googlestadia/vsi-lldb