Wait for change on LocationManager's broadcast

Instead of going through settings to change the location mode, use the
proper APIs exposed by LocationManager to command the change and wait
for the change to take effect.

Bug: 163981473
Test: atest NetworkScanApiTest --rerun-until-failure
Merged-In: Ib4b2dd3a343817f2591a85115d7cf79ad97d06ac
Change-Id: Ib4b2dd3a343817f2591a85115d7cf79ad97d06ac
(cherry picked from commit da419d3414c027390f5de5810d18486988100968)