legacy: Remove unused hci event handlers and support am: cc09855f am:...

legacy: Remove unused hci event handlers and support am: cc09855f am: 7ec8c69a am: f2820ac8 am: 0e0b1789

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Bluetooth/+/2000497

Change-Id: Ic1ab8b50e7cc34b8e2df9d2c3c65886aa9ff3817