Fixing static_test.sh issues when using zsh

Summary:
Fixing the issue of getting a mutli line string variable for a find
command in zsh. We now replace all new lines in that using sed.

Test Plan:
Verify that the script works on both zsh and bash as login
shell.

Reviewers: jevripio

Reviewed By: jevripio

CC: phab

Differential Revision: https://sibld.phab.dev.bloomberg.com/D129