Update faded color opacity in NotificationProgressBarTest.

Latest update in production code was ag/30895206. Missed updating it
correspondingly in tests. Looks like the tests in this directory aren't
included in Presubmit.

Flag: android.app.api_rich_ongoing
Bug: 383557351
Test: NotificationProgressBarTest
Change-Id: Iefccd622e5ecf6ac5a468d757cce636d0c5844c6