Bluetooth: OPP: Add locale support for OPP file transfer progress text

Display string '%' item in format progress text through localized
version of getString() instead of as hardcoded item from code.

Change-Id: I7ee432af21ced052130c90b66457a5476ba7b96e
(cherry picked from commit 2f52d3624368e629a86fc40d8e6c7b5ffc38bdcd)
(cherry picked from commit e08112badabf1da2980b7d4337034da56d2e046b)
(cherry picked from commit 3289bea4fb4ff39fcd3e1afabf5fa63ff5daf9f4)