Clarify/simplify ContentPreviewCoordinator lifecycle am: e2463f3c11

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/modules/IntentResolver/+/20424561

Change-Id: I18dcb61ed3c383a142ef60f2a9f8d6b72253b457
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>