Implemet method focus() for modal

[iamAbhi-916]

[chiaramooney]

Please do not file issues with no issue description. All issues should be using an issue template. Flagging as Needs: Author Feedback. Please add information to this issue such as what the expected behavior of the property is and an implementation plan.

Based on our documentation, it looks like focus() has been implemented. Is it not working specifically for Modal? Have you tested that this isn't working?