RootCanal: Make own copy of hci_packets.pdl

- Preparation for migrating RootCanal to github,
  removing the final dependencies to the bluetooth stack

- Will allow editing of the hci_packets.pdl source
  without incurring large changes in gabeldorsche

Bug: 256013143
Test: mmm packages/modules/Bluetooth
Change-Id: If79872ca4857786d8bd7a33f5674aa6b7ea15746