Update documentation related to A-GPS modes.

MS-Assisted has only be supported for legacy reasons for a while now.
This change moves gps.h in a direction where MS-Based (on device
computation with AGPS/Supl support) is the preferred mode to compute
locations in the device.

Change-Id: Id34a84bae79be52a435b78d249fb5b86a5f6b090
1 file changed