Gapbondmgr null pointer access

The implementation of gapBondMgr function gapBondMgrAddBond() will attempt to pass Key information to gapBondMgrSaveBond() that has not been exchanged in the pairing.
Key exchange is configured in each devices Key Distribution List. The devices exchange Key Distribution lists in Pairing Request and Pairing Response,

Issue was observed when attempting pairing/bonding with an iPhone 11.

The function gapBondMgrAddBond() attempts to pass sub-elements of pSingingInfo (CSRK) and pIdentityInfo (IRK) to gapBondMgrSaveBond().

If these Keys are not configured in Key Distribution, both of these pointers will be NULL.
This leads to a MEMFAULT exception when attempting to access sub-elements.

Proposed fix:

The irk, srk, and signCounter pointers are only evaluated and passed to gapBondMgrSaveBond() if we have the Identity Info and Signing Info respective