Fix the initial state for flashMode and torchMode

[jlapp9]

Summary

Fix for #518.

On Android, when passing an initial or static value for the flashMode or torchMode props that should result in the flash turning on, the value is not actually applied to the camera and the flash does not turn on. With a simple example such as: <Camera torchMode="on" /> the flash/torch does not turn on. Similarly <Camera flashMode="on" /> (or "auto" in a low-light environment) does not turn the flash on during photo capture. The same goes for a state variable with an initial value that should turn the flash on such as:

const [torchMode, setTorchMode] = useState(true);
return <Camera torchMode={torchMode} />;

However changing those values based on user input (i.e. using a state variable) or even a setTimeout() in a useEffect() like one of the proposed workarounds in #518 after the camera has initialized does work.

This PR resolves that issue by setting the flashMode and torchMode after the camera has initialized.

How did you test this change?

Tested on a few different Android devices using the examples above.

[jlapp9]

The build is failing, but I don't think it's due to my change. If it is, please let me know and I will address it.