Revert "d710: disable WiMAX for now"

This reverts commit 9da998eccfdf6af03e357722f47e13e6e76832b0.
d710: temporarily remove wimax from networkAttributes

Currently results in an NPE when calling startMonitoring for the
WIMAX tracker, which prevents the Connectivity Service from starting.
Disable the wimax network attribute until it's fixed.