Remove toggles in battery settings.

In Android P, we only show "Battery saver" and "Power management"
in battery settings. So we need to remove other preferences.

Keep "Battery percentage" toggle for now because it is not
cross-listed in other places.

Bug: 71502850
Test: Screenshot
Change-Id: Ia3c919f61239ff71f9343f2bce961aa4b89533c0