Property checking in host objects

## Bug Description
The behaviour described below has been noticed by us since many years now but we never had an issue with it until now.
Now that we run three.js on top of host objects, we have less flexibility on how they could behave.
I also acknowledge that this wouldn't be a problem if we were using native state instead of host objects.

The following:
```
!!("put any name" in hostHobject) // Will always return true no matter what
```

@tmikov there is probably a semantic that I am missing here, if you could refresh me on what is the semantic here? Could this be a bug? I'm not sure.

Start by reproducing the `in` expression against a host object in Hermes and inspect the host-object property-checking path. Clarify the intended JavaScript semantics with the issue’s reporter, then add regression coverage showing the expected result for an absent property. Done means the behavior is specified and the check no longer always returns true.

Written by the indexing model from the issue text.