btsocket: Inclusive language update

Replaces non-inclusive terms with "central", "temporary", and
"accept list".

It seems nobody is using these replaced terms, so it gets replaced
only here.

BUG=none
TEST=Build btsocket with:
         cros_workon --host start btsocket
         sudo emerge btsocket
     Then run AVL test.
Change-Id: Icd88b122589f52e2e2e697976436697ef9ec1e78