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

Bug: 65488978
Test: RunSettingslibRoboTests

Change-Id: I682daa3eeb5022beb90a95763c70d19d32d54915

src/com/android/settings/bluetooth/BluetoothDetailsHeaderController.java

@@ -51,8 +51,8 @@ public class BluetoothDetailsHeaderController extends BluetoothDetailsController
     }
 
     protected void setHeaderProperties() {
-        final Pair<Drawable, String> pair = Utils.getBtClassDrawableWithDescription(
-                mContext, mCachedDevice,
+        final Pair<Drawable, String> pair = com.android.settingslib.bluetooth.Utils
+                .getBtClassDrawableWithDescription(mContext, mCachedDevice,
                 mContext.getResources().getFraction(R.fraction.bt_battery_scale_fraction, 1, 1));
         String summaryText = mCachedDevice.getConnectionSummary();
         mHeaderController.setLabel(mCachedDevice.getName());