Store and report the union of SDP and BLE UUIDs.

We can discover UUIDs through SDP on classic or through GATT discovery
procedures in BLE. Currently, whichever finishes later ends up
overwriting the UUIDs discovered by the former. So if we first discover
some UUIDs using SDP and store them in the config file and then later
kick off a BLE discovery, when BLE reports discovered UUIDs we do not
check if there are any existing UUIDs discovered via SDP and happily
overwrite the config file with only the UUIDs discovered through BLE.

Bug: 235407715
Tag: #refactor
Test: Manual tests using JBL5 since we discover some UUIDs on it using
BLE and SDP. I made sure that the union of those is reported to Java.

Merged-In: I0c12296441e9c61ea766a969e6294ea192d9a1c4
Change-Id: I0c12296441e9c61ea766a969e6294ea192d9a1c4