Use one type for UUID (1/5)

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: Ia42d3233146db0488728ed6f878f99b368fe8838
Change-Id: Ia42d3233146db0488728ed6f878f99b368fe8838