Update NDK to r22b

Context: https://github.com/android/ndk/wiki/Changelog-r22#r22b
Context: android/ndk#1427

Upstream changes:

  * [Issue 1377][0]: Fix Clang backend crash in register scavenging.
  * [Issue 1388][1]: Fixed LLVM's incorrect conversion to list files for long command lines on Windows.
  * [Issue 1391][2]: Fixed missing symbols from libz.a.
  * [Issue 1427][3]: Fixed Clang auto-detection for CMake 3.19 and older for Windows.

Fix for issue 1427 above allows us to remove the older Android cmake
toolchain file we've been using to work around the bug on Windows
platforms.

[0]: android/ndk#1377
[1]: android/ndk#1388
[2]: android/ndk#1391
[3]: android/ndk#1427

build-tools/xaprepare/xaprepare/ConfigAndData/BuildAndroidPlatforms.cs

@@ -5,8 +5,8 @@ namespace Xamarin.Android.Prepare
 {
 	class BuildAndroidPlatforms
 	{
-		public const string AndroidNdkVersion = "22";
-		public const string AndroidNdkPkgRevision = "22.0.7026061";
+		public const string AndroidNdkVersion = "22b";
+		public const string AndroidNdkPkgRevision = "22.1.7171670";
 
 		public static readonly List<AndroidPlatform> AllPlatforms = new List<AndroidPlatform> {
 			new AndroidPlatform (apiName: "",                       apiLevel: 1,  platformID: "1"),

build-tools/xaprepare/xaprepare/Steps/Step_Android_SDK_NDK.cs

@@ -147,15 +147,6 @@ bool AcceptLicenses (Context context, string sdkRoot)
 
 		bool GatherNDKInfo (Context context)
 		{
-			if (context.OS.IsWindows) {
-				// Quick hack to test https://github.com/android/ndk/issues/1427#issuecomment-763424992
-				Log.Info ("Copying NDK r21 CMake toolchain file to NDK r22 directory");
-				Utilities.CopyFile (
-					Path.Combine (BuildPaths.XamarinAndroidSourceRoot, "src-ThirdParty", "ndk", "android.toolchain.cmake.ndk_r21.3"),
-					Path.Combine (context.Properties.GetRequiredValue (KnownProperties.AndroidNdkDirectory), "build", "cmake", "android.toolchain.cmake")
-				);
-			}
-
 			// Ignore NDK property setting if not installing the NDK
 			if (!DependencyTypeToInstall.HasFlag (AndroidToolchainComponentType.BuildDependency))
 				return true;