Fix(Image.resolveAssetSource) do not mock function in tests

It's purely a JS function, we can not mock it - I would say more, we should not mock it in test and ensure something is returned (for example react native fast image relies on this function to compute the URL of its component, without this fix, every URLs disappear in snapshots - see facebook#41957)

packages/react-native/Libraries/Image/__tests__/Image-test.js

@@ -291,4 +291,9 @@ describe('<Image />', () => {
     expect(secondInstance).toBe(null);
     expect(imageInstancesFromCallback.size).toBe(0);
   });
+
+  it('should resolve asset source even when Image module is mocked', async () => {
+    const resolvedSource = Image.resolveAssetSource({uri: 'foo-bar.jpg'});
+    expect(resolvedSource).toEqual({uri: 'foo-bar.jpg'});
+  });
 });

packages/react-native/jest/setup.js

@@ -119,7 +119,6 @@ jest
     Image.prefetch = jest.fn();
     Image.prefetchWithMetadata = jest.fn();
     Image.queryCache = jest.fn();
-    Image.resolveAssetSource = jest.fn();
 
     return Image;
   })