Port Update the testing script to run with the community template (facebook#45064)

Summary:
Pull Request resolved: facebook#45064

This changes port back in main the changes we made in the Stable branch with facebook@b236f9b

## Changelog:
[Internal] - Update release testing to work with the new template

Reviewed By: cortinico

Differential Revision: D58782241

fbshipit-source-id: be9f6d4310d3a83e6cc0df4bb690c746229c7ae3

Author: cipolleschi

scripts/release-testing/test-e2e-local.js

@@ -19,7 +19,6 @@
 
 const {REPO_ROOT} = require('../consts');
 const {initNewProjectFromSource} = require('../e2e/init-template-e2e');
-const updateTemplatePackage = require('../releases/update-template-package');
 const {
   checkPackagerRunning,
   launchPackagerInSeparateWindow,
@@ -245,6 +244,11 @@ async function testRNTestProject(
   const buildType = 'dry-run';
 
   const reactNativePackagePath = `${REPO_ROOT}/packages/react-native`;
+  const templateRepoFolder = '/tmp/template';
+  const pathToTemplate = path.join(templateRepoFolder, 'template');
+
+  // Cleanup template clone folder
+  exec(`rm -rf ${templateRepoFolder}`);
   const localNodeTGZPath = `${reactNativePackagePath}/react-native-${releaseVersion}.tgz`;
 
   const mavenLocalPath =
@@ -282,18 +286,32 @@ async function testRNTestProject(
     }
   }
 
-  updateTemplatePackage({
-    'react-native': `file://${newLocalNodeTGZ}`,
-  });
+  // Cloning the template repo
+  // TODO: handle versioning of the template to make sure that we are downloading the right version of
+  // the template, given a specific React Native version
+  exec(
+    `git clone https://github.com/react-native-community/template ${templateRepoFolder} --depth=1`,
+  );
+
+  // Update template version.
+  const appPackageJsonPath = path.join(pathToTemplate, 'package.json');
+  const appPackageJson = JSON.parse(
+    fs.readFileSync(appPackageJsonPath, 'utf8'),
+  );
+  appPackageJson.dependencies['react-native'] = `file:${newLocalNodeTGZ}`;
+  fs.writeFileSync(appPackageJsonPath, JSON.stringify(appPackageJson, null, 2));
 
   pushd('/tmp/');
 
   debug('Creating RNTestProject from template');
 
+  // Cleanup RNTestProject folder. This makes it easier to rerun the script when it fails
+  exec('rm -rf /tmp/RNTestProject');
+
   await initNewProjectFromSource({
     projectName: 'RNTestProject',
     directory: '/tmp/RNTestProject',
-    templatePath: reactNativePackagePath,
+    templatePath: templateRepoFolder,
   });
 
   cd('RNTestProject');