Fixed the HCI ACL Header definitions for PB and BC Flags

The byte offsets for Packet Boundary (PB) and Broadcast (BC) flags
in the HCI ACL Header is swapped. This will fixed it so that it matches
the Bluetooth Specifications.

Bug: 63241720
Test: Run manual VTS tests for Bluetooth
Merged-In: Ifc1f4d4f054a1dab13458c563e47bfb884f39d92
Change-Id: Ifc1f4d4f054a1dab13458c563e47bfb884f39d92
(cherry picked from commit 7915b71f)
(cherry picked from commit 5c981154)