Theme constructor
Theme(})
Creates a custom Theme.
For iOS, you can specify a custom tintColor, primaryColor,
backgroundColor, menuBackgroundColor and toolbarBackgroundColor.
For Android, you need to create XML files in
android/app/src/main/res/values declaring a custom style and then pass
the identifier of the style.
Please do not use light, dark or dynamic for the identifier as
these identifiers are already assigned by the SDK.
Implementation
Theme(this.identifier,
{this.tintColor,
this.primaryColor,
this.backgroundColor,
this.menuBackgroundColor,
this.toolbarBackgroundColor});