Remove released flag SMARTSPACE_DATE_WEATHER_DECOUPLED and its use sites.

Also, fixed a mistake in LSController.filterSmartspaceTarget. After the
flag value in LSControllerTest, the mistake was caught by the following
unit tests:
   - testSettingsAreReloaded
   - testSensitiveTargetsAreFilteredOutForAppropriateUsers
   - testRecognizeSwitchToSecondaryUser
   - testAllTargetsAreFilteredExceptWeatherWhenNotificationsAreDisabled
I believe the mistake caused a regression on filtering sensitive targets
for work profile. See http://b/277963509#comment14 for more details.

Flag: LEGACY SMARTSPACE_DATE_WEATHER_DECOUPLED NEXTFOOD
Bug: 309825884
Bug: 277963509
Test: unit (see updated Test files)
Test: on device, trigger alarm, dnd, timer, calendar
Change-Id: I33075849ca95c1bab5f9260eaf7506513883efef