Move the bluetooth icon logic to settingslib

This cl contains the moving about:
1. Several methods in Bluetooth/Utils.java
2. Bluetooth icon drawables
3. Bluetooth strings
4. Tests

After this cl, in quick settings detail page we could display
specific bluetooth icon(i.e. laptop, phone) with battery level.

Bug: 65488978
Test: RunSettingslibRoboTests

Change-Id: I92d2780825a986e40404dd4651e45914ca9a09eb