Remove unused react-native Animated mock

This mock appears to be unnecessary for our current test suite. It also
leveraged an internal module path, which is brittle. It would break if
React Native decided to alter its path.

If we need to reinstate this mock in the future, we should likely
explore the following approach instead. https://git.io/JtNmU

test/native/setup.js

@@ -115,9 +115,6 @@ jest.mock( 'react-native-reanimated', () => {
 	return Reanimated;
 } );
 
-// Silence the warning: Animated: `useNativeDriver` is not supported because the native animated module is missing
-jest.mock( 'react-native/Libraries/Animated/src/NativeAnimatedHelper' );
-
 // We currently reference TextStateInput (a private module) within
 // react-native-aztec/src/AztecView. Doing so requires that we mock it via its
 // internal path to avoid "TypeError: Cannot read property 'Commands' of