flow: Remove handleImagePress from Lightbox props.
flow: Remove handleImagePress from Lightbox props.

There is no handleImagePress prop that is passed to Lightbox.
At the time of this commit, handleImagePress is a prototype method
that updates local state.

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