BT discovery test with mobly snippet and spectatio

Bug: 289129602
Test: 1. install automotivesnippet on auto

```
adb -s <serial> install -d -r -g ~/AutomotivePhoneSnippet.apk
```

2. install mbs on phone

```
adb -s <serial >install -d -r -g ~/mobly-bundled-snippets-debug.apk
```

3. run test with [config](https://paste.googleplex.com/5036496280092672)

```
make BTDiscoveryTest
local_mobly_runner.py -m BTDiscoveryTest -c ./config.yaml
```
 results: https://paste.googleplex.com/6033315441147904

Change-Id: I8fd120adb6f120025427741926350aa8bb5b7fc1
2 files changed