[AsyncHybridViewInflation] Fix crash in Historic Message handling

groupMessages throws ArrayIndexOutOfBoundsException when there is historic message.
This CL make this change inline with the logic in ConversationLayout.

Bug: 217799515
Test: check Add Historic for MessagingStyle Notification and add notification. Observe no crash
Flag: ACONFIG notification_async_hybrid_view_inflation DEVELOPMENT
Change-Id: Ic2c1d8d5bf1df209a876168469e0e82fe0225f1e