Re-arrange settings and captions for dreams. Activation on sleep
and activation on dock now independent. Sleep activation defaults to off,
dock activation defaults to on (replacing dock mode).
Also use dream manager service for testing dream preference, and properly
disable preferences if both dream activations are disabled.
Change-Id: I76f5ba115c7678826a09077dd393acc55c2bca26
Bug: 6921930
Additionally, hide all Dreams settings if the feature is
disabled (R.bool.config_enableDreams).
(Depends on change Idfe9d430)
Change-Id: Ifa05f125e411ca58605c33481de26cd29a926807
Depends on change Ied691856 for
Settings.Secure.DREAM_TIMEOUT and
Settings.Secure.DREAM_COMPONENT.
Change-Id: Ib6f74b74036e12637efb891b97e459a4e33444e7