Stack Should not Allow Slave Security Requests to be Sent once Pairing has Started

Problem Description

The spec states that "The slave shall not send the Security Request command if the pairing procedure is in progress, or if the encryption procedure is in progress.”

However, there is no check in the stack to prevent this. Customer is continuously sending this (since some phones don't respond to the first one) and once the iPhone receives this during pairing, it stops the pairing procedure.

Reproduction

1. Set a timer to continuously send a Slave Security Request
2. Start pairing
3. See that the Slave Security Requests are still sent during pairing