Camera direction support for both iOS and Android.

[kyosifov]

Platforms affected

• iOS
• Android

Motivation and Context

I used the plugin in my app and couldn't use the front end camera. This inspired me to contribute, so we can allow for such access.

Description

Adds an optional cameraDirection property for choosing either front-facing or back camera.

Testing

I installed it in my app.

Checklist

• [x] I've updated the documentation if necessary

[kyosifov]

Is there a problem, that blocks this from being merged?