bug added missing Microsoft Xbox's build targets (using in 2020.3.x and higher)

[am1goo]

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Pull Request Details

Before changes: after entering in Play mode in Unity Editor, Facebook wrapper produce exception:

ArgumentException: Requested value 'GameCoreScarlett' was not found.
System.Enum+EnumResult.SetFailure (System.Enum+ParseFailureKind failure, System.String failureMessageID, System.Object failureMessageFormatArgument) (at <695d1cc93cca45069c528c15c9fdd749>:0)
System.Enum.TryParseEnum (System.Type enumType, System.String value, System.Boolean ignoreCase, System.Enum+EnumResult& parseResult) (at <695d1cc93cca45069c528c15c9fdd749>:0)
System.Enum.Parse (System.Type enumType, System.String value, System.Boolean ignoreCase) (at <695d1cc93cca45069c528c15c9fdd749>:0)
Facebook.Unity.Editor.PlayModeStateChanged.OnPlayModeStateChange (UnityEditor.PlayModeStateChange state) (at <d94eaa45a06f4a28b0b54293a88028d7>:0)
UnityEditor.EditorApplication.Internal_PlayModeStateChanged (UnityEditor.PlayModeStateChange state) (at <25578071f6e44201aac745680e5c8dfc>:0)

After changes: clear log

Test Plan

Test Plan: nothing to test