想读取虚拟器里面的图片，加载到内存位图，出现这个错误：
Unable to decode stream: java.io.FileNotFoundException: /mnt/media_rw/sdcard/Pictures/p11su.jpg: open failed: EACCES (Permission denied) Unable to decode
Unable to decode stream: java.io.FileNotFoundException: /mnt/media_rw/sdcard/Pictures/p11su.jpg: open failed: EACCES (Permission denied) Unable to decode
