Fix time stats in bluetooth_manager dumpsys

1. If an application starts an unfiltered scan on screen-off
then it is immediately suspended. However, the "Suspended Time"
for such a scan is not updated in bluetooth_manager dumpsys.
With this change "Suspended Time" is updated for such scans as below:

2017/08/10 15:04:01 - 5945ms Suspended 0 results (6)
      └ Suspended Time: 5942ms

2. Fix a bug in calculating "Total time suspended".

Test: Tested BLE scanning application with screen off.
Change-Id: I489cf5d6854e10fc25d4ce8e7817126391d0bc89