leaudio: Fix regression on data path removal

This patch fix typo regression after

b6523f3a leaudio: Fix for removing data path

Also improves unit test which catch that.

Bug: 242936102
Test: atest BluetoothInstrumentationTests
Tag: #feature
Change-Id: I346aafb6f2a364efe51179ed87434e16f4605a49