a11y: Add accessibility label to ComponentWithOverlay
a11y: Add accessibility label to ComponentWithOverlay

This component is used in several places, mostly by NavButton
and several icon components. In order to make these components
accessible we a11y-enable their parent component.

vishwesh3/zulip-mobile,vishwesh3/zulip-mobile,vishwesh3/zulip-mobile,vishwesh3/zulip-mobile