Fix misnamed targets file in nuspec

Author: Redth

transition/nuget/Xamarin.Android.Support.Transition.nuspec

@@ -24,7 +24,7 @@
     </dependencies>
   </metadata>
   <files>
-    <file src="transitions/nuget/Xamarin.Android.Support.Transition.targets" target="build" />
+    <file src="transition/nuget/Xamarin.Android.Support.Transition.targets" target="build" />
 
     <file src="output/Xamarin.Android.Support.Transition.dll" target="lib/MonoAndroid70" />
   </files>