Changed enum values to lowercase

packages/camera/camera_platform_interface/lib/src/types/image_format_group.dart

@@ -34,33 +34,33 @@ enum ImageFormatGroup {
 /// Extension on [ImageFormatGroup] to stringify the enum
 extension ImageFormatGroupName on ImageFormatGroup {
   /// returns a String value for [ImageFormatGroup]
-  /// returns 'UNKNOWN' if platform is not supported
+  /// returns 'unknown' if platform is not supported
   /// or if [ImageFormatGroup] is not supported for the platform
   String name() {
     if (defaultTargetPlatform == TargetPlatform.android) {
       switch (this) {
         case ImageFormatGroup.jpeg:
-          return 'JPEG';
+          return 'jpeg';
         case ImageFormatGroup.yuv420:
-          return 'YUV420';
+          return 'yuv420';
         case ImageFormatGroup.bgra8888:
         case ImageFormatGroup.unknown:
         default:
-          return 'UNKNOWN';
+          return 'unknown';
       }
     } else if (defaultTargetPlatform == TargetPlatform.iOS) {
       switch (this) {
         case ImageFormatGroup.bgra8888:
-          return 'BGRA888';
+          return 'bgra8888';
         case ImageFormatGroup.yuv420:
-          return 'YUV420';
+          return 'yuv420';
         case ImageFormatGroup.jpeg:
         case ImageFormatGroup.unknown:
         default:
-          return 'UNKNOWN';
+          return 'unknown';
       }
     }
     // unsupported platform
-    return 'UNKNOWN';
+    return 'unknown';
   }
 }

packages/camera/camera_platform_interface/test/method_channel/method_channel_camera_test.dart

@@ -26,7 +26,7 @@ void main() {
             methods: {
               'create': {
                 'cameraId': 1,
-                'imageFormatGroup': 'UNKNOWN',
+                'imageFormatGroup': 'unknown',
               }
             });
         final camera = MethodChannelCamera();
@@ -112,7 +112,7 @@ void main() {
             methods: {
               'create': {
                 'cameraId': 1,
-                'imageFormatGroup': 'UNKNOWN',
+                'imageFormatGroup': 'unknown',
               },
               'initialize': null
             });
@@ -136,7 +136,7 @@ void main() {
             'initialize',
             arguments: {
               'cameraId': 1,
-              'imageFormatGroup': 'UNKNOWN',
+              'imageFormatGroup': 'unknown',
             },
           ),
         ]);