ACL: Refactor remote version/feature response

Separate the packet parsing and handling part, so that we can parse the
packet in GD L2cap and handle it in legacy stack.
When GD L2cap is enabled, don't send these request in legacy stack.

Tag: #gd-refactor
Bug: 141555841
Test: cert/run --host
Test: Pair and connect with a headset
Change-Id: I8be299f1e61cb790ce0d0b7a81d3e6a99bc8d336