Add Connectivity Engine (CnE) WQE support

Enhanced connectivity features viz. Wifi Quality Estimation.
Supports dual network mode - wifi & mobile simultaneously.
Use QcConnectivityService when CnE is enabled for all CnE features.

Change-Id: I14b02e21515bfc1b5fd2fc4f28e5190fa80f83f8

server: Initialize ConnectivityService on low memory device

Skip initialization of QcConnectivityService and
use ConnectivityService.java for a low memory device

CRs-Fixed: 531430

Change-Id: I2111ec32f6e40ca79b7fc91ec4cef97ac27f3b3a