Bluetooth reset observed as device record allocation failed

Steps to reproduce: |-
1. Turn on BT
2. Pair and connect remote
3. disconnect
4) reconnect remote
5) turn off bt
6) turn on bt

Repeat steps 4 to 5
-

Observed result: null pointer dereference seen whiel accesing device record

Root cuase: When bluetooth turning off and if any connection intiated from
app during off, device record allocation fails as device
record structure already cleared

Fix:  Handle dev record allocation failure

Test: atest automated-test
bug: 382606183
Flag: EXEMPT bugfix

Change-Id: Iea5b768bf7c61289b72136dad7edf5f9ddac4088