[Video] Enter/exit animations for video in composer (#5164)

* enter/exit animations for video in composer

* use zoom out animation

* unify margin between different steps

* skip animation when posting

src/view/com/composer/videos/SubtitleDialog.tsx

@@ -34,7 +34,7 @@ export function SubtitleDialogBtn(props: Props) {
   const {_} = useLingui()
 
   return (
-    <View style={[a.flex_row, a.mt_xs]}>
+    <View style={[a.flex_row, a.my_xs]}>
       <Button
         label={isWeb ? _('Captions & alt text') : _('Alt text')}
         accessibilityHint={

src/view/com/composer/videos/VideoTranscodeProgress.tsx

@@ -35,7 +35,6 @@ export function VideoTranscodeProgress({
     <View
       style={[
         a.w_full,
-        a.mt_md,
         t.atoms.bg_contrast_50,
         a.rounded_md,
         a.overflow_hidden,