DO NOT MERGE Revert "new System API for preferred network mode"

This reverts commit 8a8832fd810710fd8fbd7868be49abff270a1013.

Reason: most of the users in this new API are not in pi-dev so this change does
not make sense in this branch.

Change-Id: I73b7834916b4f45017010c45e96ea2538e952443
2 files changed