Indent C++ method declarations

Summary:
This moves the `indent` function into a `Utils` module so it can be also used to properly indent the abstract methods declarations in a C++ TurboModule spec.

Changelog:
Internal

Reviewed By: nlutsenko

Differential Revision: D34704456

fbshipit-source-id: 88a3a672e4860927b5dd1f5107f40da7b5a83e51

packages/react-native-codegen/src/generators/modules/GenerateModuleH.js

@@ -19,6 +19,7 @@ import type {
 
 import type {AliasResolver} from './Utils';
 const {createAliasResolver, getModules} = require('./Utils');
+const {indent} = require('../Utils');
 const {unwrapNullable} = require('../../parsers/flow/modules/utils');
 
 type FilesOutput = Map<string, string>;
@@ -32,7 +33,7 @@ protected:
   ${hasteModuleName}CxxSpecJSI(std::shared_ptr<CallInvoker> jsInvoker);
 
 public:
-${moduleProperties}
+  ${indent(moduleProperties, 2)}
 
 };`;
 };
@@ -57,6 +58,7 @@ const FileTemplate = ({
 
 namespace facebook {
 namespace react {
+
 ${modules}
 
 } // namespace react