Fix VendorVibrationSessionTest cleanup

Update vendor session test cleanup to use cancel signal to stop any
ongoing session request from interrupting other tests.

Update test parameters to include a test label string to best match
multiple test runs in CI.

Fix: 377993239
Test: atest atest --rerun-until-failure 100 VendorVibrationSessionTest
Flag: EXEMPT test only
Change-Id: I1031c480f1997f56a7fd97acf1786148fd970128