Bluetooth: Prevent BT crash using adb commands

Use case:
Run below commands
1) adb shell am broadcast -n
    com.android.bluetooth/com.android.bluetooth.opp.BluetoothOppReceiver
2) adb shell am broadcast -n
    com.android.bluetooth/com.android.bluetooth.opp.BluetoothOppHandoverReceiver

Failure:
"Unfortunately, Bluetooth share has stopped" error comes.

Fix:
Add null check while processing with intent to fix Low severity
vulnerability in Bluetooth: Denial of Service.

Fixes: 130785642
Test: Performed sanity with above mentioned use case.
Change-Id: I0aadd14ba7f61d1b738f0a74d444e96ab82f86f1