Add status to BleDisconnectedException

Summary

The status param of onConnectionStateChange provides useful information even when new state is disconnected, since it holds the reason for disconnection, if supplied by the remote peer.

From Bluetooth Core Specification v5.0, Vol 2, Part E:

7.1.6  Disconnect Command

Command Parameters:

Reason: 
  Size: 1 octet

Value:
  0x05, 0x13-0x15, 0x1A, 0x29, 0x3B

Description:
  Authentication Failure error code (0x05), 
  Other End Terminated Connection error codes (0x13-0x15), 
  Unsupported Remote Feature error code (0x1A), 
  Pairing with Unit Key Not Supported error code (0x29),
  Unacceptable Connection Parameters error code (0x3B).

I believe it is also possible to get status 0x8 (Supervision Timeout), 0x3e (Connection Establish Timeout), and 0x16 (Connection Terminated By Local Host) in a disconnect callback, when it is triggered by the local host stack.

Library version

1.4.0

Preconditions

Connection state change event indicating a disconnect with a non-zero status. Relevant code is at RxBleGattCallback.java#L76.

Actual result

BleDisconnectedException without a status value.

Expected result

BleDisconnectedException with a status value.

[hoanglm4]

I think BleDisconnectedException with a status value is great.

[RobLewis]

Possibly irrelevant comment @ThunderThrash: I’m struggling right now with error 0x81, which is reportedly a “generic Bluetooth error”, i.e., seems to have no diagnostic value whatever. Enlightenment appreciated!