Disable UWB before starting VtsHalUwbTargetTest

VtsHalUwbTargetTest opens/closes UWB HAL multiple times.
However UWB HAL only accepts 1 client at a time so if
UWB is enabled Android Framework will have UWB HAL open
and prevent any other client from opening it.

Matching NFC VTS behavior from VtsAidlHalNfcTargetTest.cpp, VtsHalUwbTargetTest now disables
UWB before running its tests.

Test: atest VtsHalUwbTargetTest
Bug: 328326697
Change-Id: I4dfff45015232bbd0a4445e42b13db3ff2d9e87c