axolotl: Set default the Bluetooth class of device

The class of device is a string with a list of uint8t values:
90,2,12

The meaning is as follows:
{Service Field, Major class, Minor class}

Service Field: 0x5A -> 90
    Bit 17: Networking
    Bit 19: Capturing
    Bit 20: Object Transfer
    Bit 22: Telephony
MAJOR_CLASS: 0x02 -> 2 (Phone)
MINOR_CLASS: 0x0C -> 12 (Smart Phone)

Bug: 217452259
Test: make -j; -- check that bluetooth.device.class_of_device is
correct

Change-Id: I24fd57bacbf6786a26f7079e7a6e9857dbe170d1
diff --git a/vendor.prop b/vendor.prop
index 3e58896..8b7e9b4 100644
--- a/vendor.prop
+++ b/vendor.prop
@@ -89,6 +89,7 @@
 vendor.voice.path.for.pcm.voip=true
 
 # Bluetooth
+bluetooth.device.class_of_device=90,2,12
 bluetooth.profile.a2dp.source.enabled=true
 bluetooth.profile.asha.central.enabled=true
 bluetooth.profile.avrcp.target.enabled=true