Corporate Privacy - (Android 9.x; Earlier versions vary)

Exit all of your apps and reboot the phone. Once the phone is to the home screen:

Go to Settings → Apps & Notifications → see all apps → Google app info page.

Go to the app storage page.

Clear app cache and storage.

Stop the app process.

Go to the app permissions page.

Turn off all permissions listed on the permissions page.

Go back to the app info page.

Disable Google app.

Go to Settings → Apps & Notifications → see all apps → Action Services info page

Go to the app storage page.

Clear app cache and storage.

Stop the app process.

Go to the app permissions page.

Turn off all permissions listed on the permissions page.

Go back to the app info page.

Disable Action Services app.

Go to Settings → Apps & Notifications → see all apps → Google Play services info page

Go to the app storage page.

Clear app cache and storage.

(This app process can not be killed)

Go to the app permissions page.

Turn off all permissions listed on the permissions page.

Go to the app notifications page.

Disable notifications.

(This app can not be disabled)

Go to Settings → Security & Location → Advanced → Device admin apps

Turn off Find My Device

Select 'Deactivate this device admin app'

Turn off Google Pay

Select 'Deactivate this device admin app'

Reboot the phone. Google Assistant, Action Services, and Google Play Services are disabled and no longer have permissions to collect your data. Be advised that apps that make use of Google Play services may no longer function correctly, either.