floss: metrics: convert device type into BlueZ compatible type

When reporting device type for paring/bonding state changes, BlueZ uses
connection types (LE v.s., BREDR) instead of device type
(LE, BREDR, DUAL). Update the Floss metrics to use the same
conventions.

However, minimal information is available regarding the paring/bonding
over which connection type at the Floss. Even the bond initiator can
use the "auto" type without specifying LE v.s., BREDR. So the type
matching is through best effort. A previously recorded connection type
will apply to the following metrics event, and an "auto" connection or
DUAL type device will be categorized as  UNKNOWN before submission.

BUG: 240781725
Tag: #floss
Test: emerge-${BOARD} floss
BYPASS_LONG_LINES_REASON: Bluetooth likes 120 lines

Change-Id: I9063ed5039d671d3ad8c79a0167eb180edac4367