The views in an Android ListView.HeaderTemplate receive null through bindings when changing the ListView.Header property

[jeanplevesque]

Current behavior

1. On Android, use ListView.Header and ListView.HeaderTemplate.
2. Change the Header property (using a binding).
3. Notice that bindings on views inside the HeaderTemplate are updated with a null value (followed by the correct value).

Expected behavior

No null should be received in bindings unless the Header property is set to null explicitly.

Environment

Nuget Package: Uno.UI

Package Version(s): 1.45

Affected platform(s):

• iOS
• Android
• WebAssembly
• WebAssembly renderers for Xamarin.Forms
• Windows
• Build tasks
• Solution Templates

Visual Studio:

• 2017 (version: )
• 2019 (version: )
• for Mac (version: )

Relevant plugins:

• Resharper (version: )

Anything else we need to know?