Reduce sniff intervals for active mode.

According to the Bluetooth HID specification, a pointing device
should have a recommended report rate of approximately 80 Hz, and
sniff interval of 18 slots for the sniff subrating mode.
Current settings set the sniff interval to 54 slots, which is
aproximately 29.6 Hz - not really enough to emulate a mouse.

Test: with a pointing device app
Change-Id: Ic3365137bcf3f5608ada37fbfa0c3233f6ef83d7