[SB][Call] Fix `assertIsCallChip` helper method in tests.

If StatusBarConnectedDisplays is disabled but the call interactor does
provide a `StatusBarIconView`, then we use the `StatusBarIconView`
instead of a hard-coded phone icon. Also, `OngoingCallTestHelper`
provides a `StatusBarIconView` by default, which is what caused these
tests to start failing (because these tests still expected a hard-coded
phone icon).

Fixes: 394948482
Bug: 364653005
Flag: TEST_ONLY
Test: atest OngoingActivityChipsWithNotifsViewModelTest
Change-Id: Ibf4ddb09c741beed8be45a8634812aaac46220e3