Update the "statschannel" system test to use the $((expression)) shell constucts instead of executing the `expr` program. (cherry picked from commit 8034819b53789b52dd1c80b0256880b506a3f31b)
Update the "statschannel" system test to use the $((expression)) shell constucts instead of executing the `expr` program. (cherry picked from commit 8034819b53789b52dd1c80b0256880b506a3f31b)