Attaching RootView to instance in RootView.startReactApplication

[mganandraj]

This is a revert of this PR: facebook@2c896d3#diff-c6c68fb9580db5698d241fdd97b31a25ca1fdc061023a1bf1959f64fc4a00743

Please select one of the following

• I am removing an existing difference between facebook/react-native and microsoft/react-native-macos 👍
• I am cherry-picking a change from Facebook's react-native into microsoft/react-native-macos 👍
• I am making a fix / change for the macOS implementation of react-native
• I am making a change required for Microsoft usage of react-native

Summary

The PR mentioned above is breaking assumption taken by our RNHost. Hence reverting the commit until we have a better solution.

Changelog

The PR mentioned above (facebook@2c896d3#diff-c6c68fb9580db5698d241fdd97b31a25ca1fdc061023a1bf1959f64fc4a00743) is breaking assumption taken by our RNHost. Hence reverting the commit until we have a better solution.

[CATEGORY] [TYPE] - Message

Test Plan

Verified the functioning of LPC and commenting in devmain.

[pull-bot]

	Warnings
⚠️	❔ Base Branch - The base branch for this PR is something other than master. Are you sure you want to merge these changes into a stable release? If you are interested in backporting updates to an older release, the suggested approach is to land those changes on master first and then cherry-pick the commits into the branch for that release. The Releases Guide has more information.

Messages

📖

📋 Verify Changelog Format - A changelog entry has the following format: [CATEGORY] [TYPE] - Message. CATEGORY may be: General macOS iOS Android JavaScript Internal (for changes that do not need to be called out in the release notes) TYPE may be: Added, for new features. Changed, for changes in existing functionality. Deprecated, for soon-to-be removed features. Removed, for now removed features. Fixed, for any bug fixes. Security, in case of vulnerabilities. MESSAGE may answer "what and why" on a feature level. Use this to briefly tell React Native users about notable changes.

Generated by 🚫 dangerJS against 763bb08

[msgharpu]

I verified that the problem we were facing is resolved.

There is no internal PR to remove the WA added earlier. Are both changes required?