1.2.0

Behavior changes: product event params are now sent as separate product attributes instead of one
custom_data JSON attribute, and logout records a logout event.

• In-app messages are shown in their own window, independent of your navigation.
• In-app messages received in the background are shown on the next app open (newest one, up to 6
  hours).
• displayed is reported only once the message is on screen.
• Notification handling always runs on the main thread.
• setUserData and setCustomUserData accept an optional fcmToken.
• The device iOS version and the SDK version are stored correctly.