Ignore non-repeating vibrations in favor of repeating vibrations.

This way we don't inadvertently cancel things like alarms and ring
tone vibrations in favor of one shot vibrations, which are typically
shorter and meant to be feedback rather than attention getting.

Test: start alarm, hit home button, see alarm vibration isn't cancelled.
Bug: 65621937
Change-Id: Ib7fcaea7bc7f101d738b72112c8d5096c4b34ca2