Google Admin allows you to set up scheduled device reboots to force ChromeOS devices to reboot daily or after a specified number of days.
This setting can be applied within Google Admin by following this path:
Devices > Chrome > Settings > Device Settings
Select the OU to which you'd like to apply the setting on the left side.
With "Device Settings" selected at the top, scroll down through the settings to the Power and shutdown section.
Under Scheduled reboot, enter the number of days you'd like to have between reboots. (i.e. 1 for daily, 2 for every two days)
Click Save to apply changes.
☝️ A note from Google on this feature: Allows you to specify the number of days after which a device restarts. Sometimes, the device might not restart at the same time of day or the restart might be postponed until the next time a user signs out. If a session is running, then a grace period of up to 24 hours applies.