Crash when using ConstraintLayout in Notification

RemoteView can only support the following layout classes:

FrameLayout

LinearLayout

RelativeLayout

GridLayout

As mentioned here

A RemoteViews object (and, consequently, an App Widget) can support the following layout classes:

• FrameLayout
• LinearLayout
• RelativeLayout
• GridLayout

And the following widget classes:

• AnalogClock
• Button
• Chronometer
• ImageButton
• ImageView
• ProgressBar
• TextView
• ViewFlipper
• ListView
• GridView
• StackView
• AdapterViewFlipper

Descendants of these classes are not supported.

Read more: https://developer.android.com/guide/topics/appwidgets/index.html#CreatingLayout