Throwing warning "require_once failed to open stream no such file or directory" in Google Sync

When I am syncing with Google it throws warning as "require_once failed to open stream no such file or directory in"

Analysis:
In 610_to_620.php, we added migration script to update google sync handlers as modules/Google/handlers/VtigerSync.php and modules/Google/handlers/Vtiger.php.

But I didn't find any folder as 'handlers' in Google modules. I had verified with pkg and packages also.

See merge request !89