Fix xamdroid project to ensure API v10 use.

Author: yfakariya

test/MsgPack.UnitTest.Xamarin.Android/MsgPack.UnitTest.Xamarin.Android.csproj

@@ -3,8 +3,6 @@
   <PropertyGroup>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
     <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <ProductVersion>8.0.30703</ProductVersion>
-    <SchemaVersion>2.0</SchemaVersion>
     <ProjectGuid>{5EDECDB4-5179-4441-974F-EC26B4F54528}</ProjectGuid>
     <ProjectTypeGuids>{EFBA0AD7-5A72-4C68-AF49-83D382785DCF};{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}</ProjectTypeGuids>
     <OutputType>Library</OutputType>
@@ -14,11 +12,11 @@
     <AndroidResgenClass>Resource</AndroidResgenClass>
     <MonoAndroidResourcePrefix>Resources</MonoAndroidResourcePrefix>
     <MonoAndroidAssetsPrefix>Assets</MonoAndroidAssetsPrefix>
-    <AndroidUseLatestPlatformSdk>True</AndroidUseLatestPlatformSdk>
+    <AndroidUseLatestPlatformSdk>False</AndroidUseLatestPlatformSdk>
     <AssemblyName>MsgPack.UnitTest.Xamarin.Android</AssemblyName>
     <SignAssembly>true</SignAssembly>
     <AssemblyOriginatorKeyFile>..\..\src\MsgPack.snk</AssemblyOriginatorKeyFile>
-    <TargetFrameworkVersion>v4.0.3</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v2.3</TargetFrameworkVersion>
     <AndroidManifest>Properties\AndroidManifest.xml</AndroidManifest>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">