Deprecate cc_binary aconfigd and the controlling flag

cc_binary aconfigd is replaced with rust_binary aconfigd-system. The
replacement is flag guarded and is already in TF full for more than a
week. Thus delete the flag and deprecate old cc_binary aconfigd.

Flag: EXEMPT flagging infra
Test: m
Change-Id: Ie9e7132d2befbd4a907b7aa3b4e3a0de8b36775d