Do not terminate SMP pairing over LE if SMP over BR/EDR is not supported

SMP would suddenly forget about ongoing LE pairing when the following conditions are met.
1. Peripheral uses the public address over LE transport.
2. Peripheral does not support CTKD over BR/EDR.
3. Devices get connected over BR/EDR transport while SMP pairing was going on over LE transport.
In such condition, SMP will generate an SMP_BR_L2CAP_DISCONN_EVT event which abruptly terminates ongoing SMP pairing.

Test: Initiate LE pairing with a dual mode peripherl using public address, at the same time connect over BR/EDR transport, do not claim BR/EDR to LE CTKD support on the peripheral.
Test: m com.android.btservices

Bug: 307178732
Change-Id: I6be1b83f2af5f6f3bdfe02a57d948e536dab646d