serverTimestamp is undefined after upgrading from v10 to v11

[READ] Step 1: Are you in the right place?

• For issues related to the code in this repository file a Github issue.
• If the issue pertains to Cloud Firestore, read the instructions in the “Firestore issue” template.
• For general technical questions, post a question on StackOverflow with the firebase tag.
• For general Firebase discussion, use the firebase-talk google group.
• For help troubleshooting your application that does not fall under one of the above categories, reach out to the personalized Firebase support channel.

[REQUIRED] Step 2: Describe your environment

• Operating System version: MacOS 12.4
• Firebase SDK version: 11
• Firebase Product: admin and functions (auth, database, storage, etc)
• Node.js version: ^16
• NPM version: ^8

[REQUIRED] Step 3: Describe the problem

Upgrading from v10 to v11 breaks admin.firestore.FieldValue.serverTimestamp(); functionality.

Steps to reproduce:

Run any set, add, update on collection, and include a timestamp on cloud function.

Downgrading back to v10 works.

What happened? How can we make the problem occur? This could be a description, log/console output, etc.

TypeError: Cannot read properties of undefined (reading 'serverTimestamp')

Relevant Code:

`collection('any').add({createdAt: admin.firestore.FieldValue.serverTimestamp()})` 

I apologize if this was mentioned somewhere else or if there are migration steps in the changelog.