Fix corner cases for BTMediaDeviceNotPairedTest
The test is failing for the first execution on just flashed build.
After open Bluetooth Audio page the issue in not reproducible.
Test execution:
```
/ssddrive/main/out/host/linux-x86/catbox/android-catbox/tools/catbox-tradefed run commandAndExit catbox-functional-bluetooth-tests --{phone}serial 875X00GEB --{auto}serial c4ba9d70 --mobly-host:mobly-par-file-name BTMediaDeviceNotPairedTest --log-level verbose
```
Bug: 306461539
Test: [log](https://paste.googleplex.com/6267065391382528)
Merged-In: I3eccec9c6602b2a8c74bd60dce86a2d3d304243e
Change-Id: I3eccec9c6602b2a8c74bd60dce86a2d3d304243e
6 files changed