Set disable timer in case of any active ACL connection

Use Case: Disable time out when atleast one active ACL connections

Steps:
1. Turn ON Bluetooth
2. Connect to any Headset
3. Turn OFF bluetooth.

Failure: Turn OFF bluetooth is failed when atleast one active ACL connections

Root Cause:i If we have one or more active ACL links, so it is not notitying
BTA_DM_DISABLE_EVT to upper layer.

Fix: Set disable timer in case of any active ACL connection

Change-Id: Ica47717119f1ab9fa9f4f5244e8483c408276a2a