Battery saver mode should disable dark mode modification

Battery saver mode should disable dark mode modification

disable toggle options and disable the dark theme drop down selection

Test: make -j64 RunSettingsRoboTests ROBOTEST_FILTER="com.android.settings.display.DarkUIPreferenceControllerTest" && \
make -j64 RunSettingsRoboTests ROBOTEST_FILTER="com.android.settings.display.darkmode.DarkModeActivationPreferenceControllerTest" && \
make -j64 RunSettingsRoboTests ROBOTEST_FILTER="com.android.settings.display.darkmode.DarkModeObserverTest" && \
make -j64 RunSettingsRoboTests ROBOTEST_FILTER="com.android.settings.display.darkmode.DarkModeScheduleSelectorControllerTest"

Fixes: 	145098277
Fixes: 145297188
Fixes: 	145254016
Change-Id: I5c81a295810cc2d9a45657978104647e9c15da46