Support excluding multiple platforms.

Summary:
Currently the schema only allows to exclude a single platform (iOS OR Android). There are cases where we need to exclude multiple. This change converts the previous `excludePlatform` string property into an `excludePlatforms` array.

Changelog:
[Internal][Changed] - Added support to exclude multiple platforms in Codegen.

Reviewed By: sammy-SC

Differential Revision: D21426950

fbshipit-source-id: eff36ffa207109274794b4b300bf6313f8286161

packages/react-native-codegen/src/generators/components/GeneratePropsJavaInterface.js

@@ -221,7 +221,10 @@ module.exports = {
       return Object.keys(components)
         .filter(componentName => {
           const component = components[componentName];
-          return component.excludedPlatform !== 'android';
+          return !(
+            component.excludedPlatforms &&
+            component.excludedPlatforms.includes('android')
+          );
         })
         .forEach(componentName => {
           const component = components[componentName];