Add a new SystemApi, getPrivilegedConfiguredNetworks(). Part 1 [DO NOT MERGE]

This is very similar to the existing
WifiManger.getConfiguredNetworks(), but it returns real preSharedKey.
This API is only used by system application.

Bug: 15703353
Change-Id: If3eaca3286e77b780272f42a28772d1d8d39db65
(cherry picked from commit 775bf6ae5d052948bcb60eaf89defa9105d7077c)
2 files changed