cleanup: Minor cleanups in PhoneStatusBarViewControllerTest

- Use @TestableLooper.RunWithLooper(setAsMainLooper = true), like other
  tests in this package, to avoid needing to wrap every call to
  ViewController creation in runOnMainSync.
- Replace legacy ArgumentCaptor with kotlin argumentCaptor

Bug: 379760792
Test: PhoneStatusBarViewControllerTest
Flag: EXEMPT test cleanup
Change-Id: Iff3f181f1e9baefaa49574c88879aaa288e607d7