[Xamarin.Android.Tools.AndroidSdk] Update SDK component for API-32 (#156)

Context: https://dl-ssl.google.com/android/repository/repository2-3.xml
Context: dotnet/android@e4b3adb

Update the preferred Android SDK component versions to the current latest
versions listed in the [Android Repository file][0]:

  * `$(AndroidSdkPlatformToolsVersion)`/platform-tools to 32.0.0
  * `$(AndroidSdkPlatformVersion)`/platform to android-32
  * `$(AndroidNdkVersion)`/NDK to 23.1.7779620

`$(AndroidSdkBuildToolsVersion)` is left at 30.0.3, even though
32.0.0 exists, so that `dx` can continue to be used, and because the
default Android SDK packages within Visual Studio only includes
30.0.3.  (The package list needs to be updated.)

[0]: https://dl-ssl.google.com/android/repository/repository2-3.xml

Author: jonpryor

src/Xamarin.Android.Tools.AndroidSdk/Xamarin.Android.Tools.Versions.props

@@ -11,10 +11,10 @@
     -->
     <AndroidSdkBuildToolsVersion Condition="'$(AndroidSdkBuildToolsVersion)' == ''">30.0.3</AndroidSdkBuildToolsVersion>
     <AndroidCommandLineToolsVersion Condition=" '$(AndroidCommandLineToolsVersion)' == '' ">5.0</AndroidCommandLineToolsVersion>
-    <AndroidSdkPlatformToolsVersion Condition="'$(AndroidSdkPlatformToolsVersion)' == ''">31.0.3</AndroidSdkPlatformToolsVersion>
+    <AndroidSdkPlatformToolsVersion Condition="'$(AndroidSdkPlatformToolsVersion)' == ''">32.0.0</AndroidSdkPlatformToolsVersion>
     <AndroidSdkEmulatorVersion Condition="'$(AndroidSdkEmulatorVersion)' == ''"></AndroidSdkEmulatorVersion>
-    <AndroidSdkPlatformVersion Condition="'$(AndroidSdkPlatformVersion)' == ''">android-31</AndroidSdkPlatformVersion>
-    <AndroidNdkVersion Condition="'$(AndroidNdkVersion)' == ''">22.1.7171670</AndroidNdkVersion>
+    <AndroidSdkPlatformVersion Condition="'$(AndroidSdkPlatformVersion)' == ''">android-32</AndroidSdkPlatformVersion>
+    <AndroidNdkVersion Condition="'$(AndroidNdkVersion)' == ''">23.1.7779620</AndroidNdkVersion>
 
     <!-- obsolete; should consider removing eventually -->
     <AndroidSdkToolsVersion Condition="'$(AndroidSdkToolsVersion)' == ''">26.1.1</AndroidSdkToolsVersion>