Mms: Catch UnsupportContentTypeException

The original code has not catched "Unsupported Content-Type" exception
resulting in force close if an mms containing an unsupported content
type is opened.

Change-Id: I9b578e2fd61ba5df9dbfbe9e6e28fb276ef89666
Author: Haixiong Zheng <haixiong.zheng@borqs.com>
Signed-off-by: Jeevaka Badrappan <jeevaka.badrappan@intel.com>
Signed-off-by: Bin Yang <bin.y.yang@intel.com>
Signed-off-by: Shuo Gao <shuo.gao@intel.com>
Signed-off-by: Bruce Beare <bruce.j.beare@intel.com>
Signed-off-by: Jack Ren <jack.ren@intel.com>
Author-tracking-BZ: 5339