Cache CoD during LE pairing

Class of device is not updated during LE pairing. This change now
ensures that the class of device is extracted through BTM interface and
updated in the device properties.

Test: mmm packages/modules/Bluetooth
Flag: com.android.bluetooth.flags.read_le_appearance
Bug: 286334644
Bug: 362367900
Change-Id: If90284e14061457916d07aa1280fafce12835246