Move import into module as specified in documentation

Author: jwittner

UnitySetup/UnitySetup.psm1

@@ -1,5 +1,7 @@
 # Copyright (c) Microsoft Corporation. All rights reserved.
 # Licensed under the MIT License.
+Import-Module powershell-yaml -Force -ErrorAction Stop
+
 class UnitySetupInstaller
 {
     [UnitySetupComponentType] $ComponentType

UnitySetup/UnitySetupInit.ps1

@@ -16,6 +16,4 @@
     WebGL = (1 -shl 13)
     Windows_IL2CPP = (1 -shl 14)
     All = (-1)
-}
-
-Import-Module powershell-yaml -Force -ErrorAction Stop
+}