l10n: Small zh-CN update

vlc-android/res/values-zh-rCN/strings.xml

@@ -91,6 +91,7 @@
     <string name="surface_fill">填充</string>
     <string name="surface_original">居中</string>
     <string name="thumbnail">缩略图</string>
+    <string name="unseekable_stream">非跳转串流</string>
     <string name="refresh">刷新</string>
     <string name="track_audio">音频轨</string>
     <string name="track_video">视频轨</string>