Allow command complete and command status with opcode 0x0 anytime

From BLUETOOTH CORE SPECIFICATION Version 5.2 | Vol 4, Part E | 4.4 COMMAND FLOW CONTROL
"The Controller can send an HCI_Command_Complete or HCI_Command_Status event with Command Opcode 0x0000 at any time to change the number of outstanding HCI Command packets that the Host can send before waiting."

Bug: 214331534
Change-Id: I5265980518f0739f56657116ff13b7f6cc73e9b9
Test: N/A, Presubmit