How do I change the Chrome installation folder on a Mac?
So figure the problem is in the above path
No. Google Chrome.app is the application package for Google Chrome. It contains one executable file, which is under Google Chrome.app/Contents/MacOS/Google Chrome.
This file is really opened by OS X when you start Google Chrome.
If Firefox is opened automatically, I presume it's set as the system wide default browser. Just go to Google Chrome's preferences and set it as the default browser. Or, as this answer suggests, to specifiy googlechrome from Selenium.
You really seem to be having an XY problem.