SettingsProvider: enable wifi by default & adjust sleep policy

* Enable wifi by default to workaround issue with SetupWizard calling invalid
  setWifiEnabled() method (changed by CyanogenMod)
* Set wifi sleep policy to always on only when plugged in
* Revert some misc customizations to defaults (rotation, sounds, tones)

Change-Id: I542b436723a3f19bb783992f45df0a67914387e1