SlideAnimationView: Delete.

We've just replaced our only use of this with something that has a
better API; see discussion [1].

Also, its interface seemed a little confused -- if it was meant to
"slide" something, I wouldn't expect callers themselves to have to
specify, e.g., `translateX` or `translateY`, over things that
clearly don't make things slide, like `rotateX` or `skewX` [2].

[1] https://chat.zulip.org/#narrow/stream/243-mobile-team/topic/.60View.60's.20.60onLayout.60.20prop/near/1110130
[2] https://reactnative.dev/docs/transforms

src/common/index.js

@@ -29,7 +29,6 @@ export { default as SearchInput } from './SearchInput';
 export { default as SectionHeader } from './SectionHeader';
 export { default as SectionSeparator } from './SectionSeparator';
 export { default as SectionSeparatorBetween } from './SectionSeparatorBetween';
-export { default as SlideAnimationView } from './SlideAnimationView';
 export { default as SmartUrlInput } from './SmartUrlInput';
 export { default as SpinningProgress } from './SpinningProgress';
 export { default as GroupAvatar } from './GroupAvatar';