Bluetooth: Add NULL check before accessing Profile data

Add NULL check for profile data before accessing them
in case of stopping the profile.Framework test activity
and BT both can start service hence while clean-up check
for null.

This check is added for A2DP, HDP, HFP-AG and HFP client
profiles.
CRs-Fixed: 597242

Change-Id: I4a1f35842084bc6ae1b496adbe0b20cf7d1d68ef