[Xamarin.Android.Tools.AndroidSdk] Probe for AdoptOpenJDK Locations (#115)

Context: https://adoptopenjdk.net
Add support to probe for the [AdoptOpenJDK][0] installation
directories.
[0]: https://adoptopenjdk.net/?variant=openjdk8&jvmVariant=hotspot

Author: jonpryor

src/Xamarin.Android.Tools.AndroidSdk/JdkInfo.cs

@@ -288,6 +288,7 @@ public static IEnumerable<JdkInfo> GetKnownSystemJdkInfos (Action<TraceLevel, st
 .Concat(JdkLocations.GetPreferredJdks(logger))
 .Concat(XAPrepareJdkLocations.GetXAPrepareJdks(logger))
 .Concat(MicrosoftOpenJdkLocations.GetMicrosoftOpenJdks(logger))
+.Concat(AdoptOpenJdkLocations.GetAdoptOpenJdks(logger))
 .Concat(AzulJdkLocations.GetAzulJdks(logger))
 .Concat(OracleJdkLocations.GetOracleJdks(logger))
 .Concat(VSAndroidJdkLocations.GetVSAndroidJdks(logger))

src/Xamarin.Android.Tools.AndroidSdk/Jdks/AdoptOpenJdkLocations.cs

@@ -0,0 +1,20 @@
+usingSystem;
+usingSystem.Collections.Generic;
+usingSystem.Diagnostics;
+usingSystem.IO;
+usingSystem.Linq;
+usingSystem.Text;
+
+namespaceXamarin.Android.Tools{
+
+classAdoptOpenJdkLocations:JdkLocations{
+
+internalstaticIEnumerable<JdkInfo>GetAdoptOpenJdks(Action<TraceLevel,string>logger)
+{
+returnGetMacOSSystemJdks("adoptopenjdk-*.jdk",logger)
+.Concat(GetWindowsFileSystemJdks(Path.Combine("AdoptOpenJDK","jdk-*"),logger))
+.Concat(GetWindowsRegistryJdks(logger,@"SOFTWARE\AdoptOpenJDK\JDK","*",@"hotspot\MSI","Path"))
+.OrderByDescending(jdk =>jdk,JdkInfoVersionComparer.Default);
+}
+}
+}