Remove the feature flag for time zone picker

Bug: 72376227
Test: m RunSettingsRoboTests ROBOTEST_FILTER=com.android.settings.datetime.timezone
Test: manual
Merged-In: I4880f8e37d53879b971890a5d83ebdf1a417a262
Change-Id: I4880f8e37d53879b971890a5d83ebdf1a417a262
(cherry picked from commit 56cb29c0c368a4d75485eabf7f3dfc2933639286)
1 file changed