Bug 990481 - [ZTE][OPENC]MMS app allows to attach more contents even when the max MMS size is reached r=zasypkin

Review Round:1 Bug 990481 - [ZTE][OPENC]MMS app allows to attach more contents even when the max MMS size is reached

Review round:2 Bug 990481 - [ZTE][OPENC]MMS app allows to attach more contents even when the max MMS size is reached