Person sensors not firing correctly when camera has multiple zones
The Person sensor does not fire for Nest cameras with multiple zones unless ALL zones in the camera fire for a person. I have my front yard and back yard cameras split into zones and the person alert for the camera only fires if you walk into all of the zones instead of just one. You get a motion alert on the zone, but there is no person alert for the zone it appears to only be at the camera level.

Steps to reproduce the behavior:

1. Setup multiple zones for a single camera in the Nest application and set them for Person alerts
2. Have a person enter into only one of the zones and Nest will alert for a Person in that zone
3. Zone trigger happens in Homebridge (not a person alert), but the Person sensor in Homebridge for the Camera as a whole does not trigger

**Expected behavior**
If a person enters any zone, the overall Person sensor for the camera should fire in Homebridge and trigger in Homekit, or add a Person trigger for each Zone as part of the system. 

Please answer these questions before submitting this issue:
```
On what device are you running homebridge: Windows 10 Computer with Node.js 14.15 as a service and Homebridge 1.2.3
On what iOS version are you having issues: 14.1
What camera types are having issues: Nest Cam IQ Outdoor
Does this issue occur consistently or randomly: Consistently
If applicable, what was the last version that worked properly: None
```
