[Invisalign2] Change the return type of btm_ble_start_sec_check

To drop the dependency on L2CAP, use tBTM_STATUS as return value
type.

Bug: 301661850
Test: m com.android.btservices
Flag: EXEMPT, no-op
Change-Id: I0b5735d6182e056b7a093ce8c369024963956e04