floss: don't add device to acceptlist if already connected

If there is already a valid handle, there is no need to add the address
to the accept list. If the device is paired with a resolvable address
(RPA), the random address is used to search the handle.

Bug: 297629431
Bug: 338112215
Test: CTSV secure client test
Test: mma -j32
Flag: verify_handle_before_add_accept_list
Change-Id: Ice1aaeccac1ea8613b6471a1e5ccc30288d9de95