Request high accuracy fix for DBH requests from GNSS HAL

The GnssLocationProvider requests a LOW_POWER fix from fused
location provider for DBH requests and uses a short request
duration of 10 secs. Change it to request a high accuracy fix
and use a larger request duration for emergency requests.

Fixes: 135458882
Test: Simulated E911 DBH request from HAL and verified that
      a location is injected to HAL when location settings
      are OFF/ON. Tested with and without GPS signal.

Change-Id: Ia40bff4cbf8574b30dfe65704d33c716a317c66d