Codemod $Enum<...> to $Keys<...> in xplat/fbcode

Summary:
In D15367312, I deprecate `$Enum<...>` in favour of `$Keys<...>` (the functionality is identical). Codemod existing usages in xplat and fbcode.

bypass-lint

Reviewed By: samwgoldman

Differential Revision: D15378084

fbshipit-source-id: 251c6b9ac07cb50139a8f03e3a45a5fac0d91812

Libraries/Components/ViewPager/ViewPagerAndroid.android.js

@@ -44,7 +44,7 @@ type PageSelectedEvent = SyntheticEvent<
   |}>,
 >;
 
-export type ViewPagerScrollState = $Enum<{
+export type ViewPagerScrollState = $Keys<{
   idle: string,
   dragging: string,
   settling: string,