Improve BT OPP throughput

Progress Bar updation during OPP takes around 40ms for each update.
This causes a significant delay in OPP file transfer, which eventually
will decrease the throughput.
To improve the throughput, invoke the progressBar updation only if there
is a change in the percentage.

Change-Id: I64a0b47093698959026d2b97f296c709a7d92703
Signed-off-by: Deepak A Metri <deepak.a.metri@intel.com>
Signed-off-by: Cedric Bondier <cedric.bondier@intel.com>
Signed-off-by: Zhiquan Liu <zhiquan.liu@intel.com>