Fix bad address type assumption

LE related code should not use BTM_ACL_IS_CONNECTED, because it assumes
classic transport.

In this particular case, connection created event, which was result of
advertising, caused cancellation of "LE Create Connection".
Attempt to send "LE Create Connection Cancel" was checking if connection
is already established, but was failing to do so becuase
BTM_ACL_IS_CONNECTED was used instead of btm_bda_to_acl with proper
transport. This caused just created connection to be dropped.

Bug: 31442085
Change-Id: Ia345a3d00e8567160f4abb2a31c4130ee69d67a3
(cherry picked from commit f5566938ba671329d91c84c30ab126fbcdfc16d7)