Make Animated.Interpolation config read-only

Summary:
Changelog:
[General] [Changed] Type the argument of Animated.interpolate as read-only

Reviewed By: javache

Differential Revision: D33950698

fbshipit-source-id: b959d34eb9752358f4a8ba1d290b56c099f535e0

Libraries/Animated/nodes/AnimatedInterpolation.js

@@ -23,14 +23,14 @@ import type {PlatformConfig} from '../AnimatedPlatformConfig';
 
 type ExtrapolateType = 'extend' | 'identity' | 'clamp';
 
-export type InterpolationConfigType = {
+export type InterpolationConfigType = $ReadOnly<{
   inputRange: $ReadOnlyArray<number>,
   outputRange: $ReadOnlyArray<number> | $ReadOnlyArray<string>,
   easing?: (input: number) => number,
   extrapolate?: ExtrapolateType,
   extrapolateLeft?: ExtrapolateType,
   extrapolateRight?: ExtrapolateType,
-};
+}>;
 
 const linear = (t: number) => t;