fix type mismatch, convert tabIndex string to number base 10#3112

mjaiswal-sfdc wants to merge 3 commits intosalesforce:mastersalesforce/design-system-react:masterfrom

mjaiswal-sfdc:fix-type-mismatch-tabIndexmjaiswal-sfdc/design-system-react:fix-type-mismatch-tabIndexCopy head branch name to clipboard