fix(types): 🐛 add camera type (react-native-image-picker#1674)

Author: Johan-dutoit

src/types.ts

@@ -12,7 +12,7 @@ export interface ImageLibraryOptions {
 export interface CameraOptions extends ImageLibraryOptions {
   durationLimit?: number;
   saveToPhotos?: boolean;
-  cameraType?: string;
+  cameraType?: CameraType;
 }
 
 export interface ImagePickerResponse {
@@ -40,6 +40,7 @@ export type PhotoQuality =
   | 0.8
   | 0.9
   | 1;
+export type CameraType = 'back' | 'front';
 export type MediaType = 'photo' | 'video';
 export type AndroidVideoOptions = 'low' | 'high';
 export type iOSVideoOptions = 'low' | 'medium' | 'high';