displayMessage
Renders inAppMessage, reporting what happens to it through callbacks: the impression, a click on one of its actions, its dismissal, or the error that kept it from being displayed. Until one of those is reported the SDK considers the message on screen and displays no other.
Renders the message with the iOS SDK's default UI, which reports to callbacks on the main thread. Reports InAppMessagingErrorReason.UNSPECIFIED_RENDER_ERROR instead on tvOS, which has no default UI.
Displays inAppMessage with the default UI, reporting to callbacks.
Android: does nothing. The display SDK renders through the component it binds itself, and this inherited member is a no-op.
iOS: renders the message with the iOS SDK's default UI.
tvOS: reports UNSPECIFIED_RENDER_ERROR, as there is no default UI.
JVM: does nothing.
Does nothing: there is no message UI on the JVM.