Dupe BluetoothSettings and DeviceListPreferenceFragment

Create the obsolete version of the belowing fragments, so we could
flip between old page and new page.

BluetoothSettingsObsolete and DeviceListPreferenceObsoleteFragment
contains all the old logic but:
1. Logic about BluetoothPairingPreferenceController(ag/2239482),
since this preference shouldn't be checked in without the flag :(

This cl also adds logic in MasterSwitchPreferenceController to flip
these two pages.

Following cl will refactor these fragment to make it compatible
to new framework.

Bug: 35877041
Test: RunSettingsRoboTests
Change-Id: I1cc1bc2d49d8a3e11c3127e56f6409fbc84028d8