Update Mono.Android.targets

Author: jpobst

src/Mono.Android/Mono.Android.targets

@@ -153,7 +153,7 @@
     </ItemGroup>
     <ItemGroup>
       <_Annotation
-          Condition=" Exists('$(AndroidSdkDirectory)\platform-tools\api\annotations.zip') "
+          Condition=" Exists('$(AndroidSdkDirectory)\platform-tools\api\annotations.zip') And !Exists('$(AndroidSdkDirectory)\platforms\android-$(AndroidPlatformId)\data\annotations.zip') "
           Include="$(AndroidSdkDirectory)\platform-tools\api\annotations.zip"
       />
       <_Annotation