Don't overzealously disable all preferences in airplane mode.

Only disable those prefs that actually need the network connection.
Fixes applying various preference summaries.

Change-Id: Id89a2572e382b28c1da100ebb1a1a73eb9233e35
Merge "Don't overzealously disable all preferences in airplane mode." into cm-11.0
Merge remote-tracking branch 'upstream/cm-11.0' into cm-11.0