Use one type for UUID (3/5)

Currently, we have few different representations for UUID in stack:
tBT_UUID, tSDP_UUID, bt_uuid_t, bluetooth:UUID, or uint8_t*.

Additionally, tBT_UUID and bt_uuid_t are used to hold UUID as 128bit
as Little Endian or Big Endian, depending on which part of stack (GATT
or SDP) is using it.

This patch is creating one type, bluetooth::Uuid, that will replace all
other types.

Bug: 66912853
Test: all sl4a tests for GATT and RFCOMM
Merged-In: Ia095898aa381f899327d1b01a71e366ccfdbb995
Change-Id: Ia095898aa381f899327d1b01a71e366ccfdbb995