feat(ui):修改一下样式

@@ -142,7 +142,7 @@ class WatchFacePreview extends StatelessWidget {
           SizedBox(
             width: themeSize.width,
             height: themeSize.height,
-            child: _buildFaceImage(themeImageUrl,
+            child: _buildFaceImage(themeImageUrl2,
                 'assets/images/watch_theme/official_default_green.png'),
           ),
           SizedBox(
@@ -151,7 +151,7 @@ class WatchFacePreview extends StatelessWidget {
           SizedBox(
             width: themeSize.width,
             height: themeSize.height,
-            child: _buildFaceImage(themeImageUrl2,
+            child: _buildFaceImage(themeImageUrl,
                 'assets/images/watch_theme/official_default_blue.png'),
           ),
         ],