Bluetooth: GAP: Rejecting the empty string in Bluetooth rename

Fix for rejecting the empty string in bluetooth
rename dialogue as part of DONE button as well as
trimming the empty string at head and tail end of
the valid string as part of both rename tab and
DONE button.

CRs-Fixed: 910174
Change-Id: I0b7472ad7777ff0b0b7e197f3c6b822e0afbb0d4
1 file changed