le_impl: connect_list -> accept_list

Search for "connect list" in BT spec gives 0 results. Term "accept list"
is used everywhere through the spec.

Bug: none
Test: m com.android.btservices
Flag: EXEMPT, minor cleanup, no logical change
Change-Id: Icc985f3f180cf9aedad6ae1e4329a0e7b0d816b5