getLiveUpdateActivityId
Tells a Live Update push apart from a regular one and returns its activityId.
A Live Update arrives as an ordinary push whose payload carries the live-update marker; this helper is the supported way to recognize one from a PushMessage — for example inside NotificationServiceExtension.onMessageOpened or onMessageCanceled — without parsing the wire format yourself. The returned id is the same value used to key endLiveUpdate and getActiveIds.
Safe to call from any thread and on any API level.
Return
the Live Update's activityId, or null if the message is not a (well-formed) Live Update push
Parameters
message
the push message to inspect