Bluetooth: Map: Avoid Illegal argument exception while messagelisting

While doing messagelisting from drafts, we see invalid symbols appended
at the end of sender addressing, causing illegal argument exception
while creating the messagelisting object. Add change to fetch the
proper address to avoid illegal argument exception in such scenarios.

Change-Id: Iba08fed16fcf6987a1ecafdd4a22382ffe2391ab
CRs-fixed: 594738