Split BluetoothSettings into two pages

This cl splits the BluetoothSettings into paired device page and
pairing page, including small changes about:
1. Refactor the pages so they could get as much as static preference
from xml file rather than dynamically add/remove them everytime.
2. Remove creating method in BluetoothDeviceNamePreferenceController
and add it in xml file
3. Create BluetoothPairingDetail page, basically move the logic from
BluetoothSettings.
4. Make pairing preference clickable and jump to BluetoothPairingDetail
5. Add and update bunch of tests

Bug: 35877041
Test: RunSettingsRoboTests
Change-Id: Ief9e9690c612f7b46c58e866e5cecc511af642c8