floss: Complete Floss to BTIF GATT attribute type conversions

Fix previously incomplete GATT attribute type conversions from Floss to
the Bluetooth Interface, including adding key size in GATT attributes,
and properly excluding included GATT Services.

Bug: 328812649
Test: m -j && manually via btclient:
Add a basic service, then add another service with the previous one as
an included service. Verify this works, and that using an incorrect
instance_id does not.
Flag: Exempt, Floss-only change

Change-Id: I62acf2124f5551eb6e4e3807796fd64b6b1818a5