MTP/PTP: disable erasing/unmount operation for SD card while MTP/PTP is active

Check the USB connection status and MTP/PTP setting, if USB connected and MTP/PTP enabled,
disable the erasing and umount operation.
Judge SD card Mounting status and keep summary string.

Change-Id: Iff3e0f25b581bc462c88fff59eb93d765baaddd7
Author: Li Gang <gang.g.li@intel.com>
Signed-off-by: Xiaokang Qin <xiaokang.qin@intel.com>
Signed-off-by: Bruce Beare <bruce.j.beare@intel.com>
Signed-off-by: Jack Ren <jack.ren@intel.com>
Author-tracking-BZ: 47043