Merge "[Ongoing call] Don't show the time if the notification's `when` value...

Merge "[Ongoing call] Don't show the time if the notification's `when` value isn't valid." into sc-dev am: 3ad556f6 am: 169f415d

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/15177730

Change-Id: I321ad668703a07200995531fe5d998d3920b818e