Mirror image for Android (#399)

* Add mirrorImage support for Android

* Release resources after mirroring

* Mirror image only for TYPE_FRONT

* Remove unnecessary annotation

* Document mirrorImage for Android

* Improved compression and error handling

* Add support for mirroring on Android back camera too

Example/Example.js

@@ -189,6 +189,7 @@ export default class Example extends React.Component {
           type={this.state.camera.type}
           flashMode={this.state.camera.flashMode}
           defaultTouchToFocus
+          mirrorImage={false}
         />
         <View style={[styles.overlay, styles.topOverlay]}>
           <TouchableOpacity