Relax conversation notification rules for audio during avalanche

 Allow CATEGORY_MESSAGE notifications to ping with sound/vibration during avalanche.

 This is needed because some apps will post conversations as groups with GROUP_ALERT_SUMMARY behavior
 and the summary notification is not a conversation notifcation or a different style than MessagingStyle.

Flag: com.android.server.notification.polite_notifications

Test: atest NotificationAttentionHelperTest
Bug: 357011208
Change-Id: I52f78daade9cf7e8a7ac3669e31829fe0cbced76