Add traffic thresholds to prevent wifi network changes

This parameters are used for refraining from changing
network when RSSI is good and there is heavy traffic
implying streaming.

A typical video streaming will move the tx above 20 pps
and rx above 40 pps.
A typical voice call will move both tx and rx rate above
16 pps.
With that being said, this patch sets both thresholds to
16 pps.

Bug: 62428282
Test: compile, unit tests, manual test
Change-Id: Id2a7546b7ca9a1370c37d3f26f3da28231757c19