[Bug] Switch control not respecting Material Design on Android

[Depechie]

Description

When using the Switch control in Xamarin Forms, we are able to change the ThumbColor. When setting this to White and also using White for the ContentPage BackgroundColor, you'll notice that the drop shadow of the Switch is gone. According to the Android Material design guidelines, the default Android implementation has this drop shadow.

Reference material from Android with also showing a White example:
https://material.io/develop/android/components/switches
https://material.io/design/interaction/states.html#usage

Steps to Reproduce

1. Open the https://github.com/xamarin/xamarin-forms-samples/tree/master/UserInterface/SwitchDemos demo
2. Change the Switch control on the SwitchXamlPage to have a ThumbColor set to White, change the ContentPage BackgroundColor also to White
3. Run the demo

Expected Behavior

Switch control should have drop shadow and a border around the thumb circle.

Actual Behavior

No border or drop shadow can be seen

Basic Information

• Version with issue: 4.8

Screenshots

[Jagan2412]

Facing same issue

[tossingc]

This issue arose when we switched the Android target to 10.0 (API 29) - TargetFrameworkVersion -> v10.0 and targetSdkVersion -> 29.

Prior to making that one change, there was a shadow under the white thumb on a white background.

Screenshot from when we were targeting v9.0 (API 28):