Revert back Android check and clarify IsLinux

Brovan/Core/Emulation/UnicornBinding/Native.cs

@@ -166,7 +166,7 @@ namespace Brovan.Core.Emulation
                 throw new PlatformNotSupportedException("Brovan currently supports resolving unicorn for Windows and Linux only.");
             }
 
-            if (string.Equals(LibName, "vulkan-1.dll", StringComparison.OrdinalIgnoreCase) && (GeneralHelper.IsLinux || Android.AndroidHost.IsActive))
+            if (string.Equals(LibName, "vulkan-1.dll", StringComparison.OrdinalIgnoreCase) && GeneralHelper.IsLinux)
             {
                 if (NativeLibrary.TryLoad("libvulkan.so.1", out IntPtr handle))
                     return handle;

Brovan/GeneralHelper.cs

@@ -166,6 +166,9 @@ namespace Brovan
     internal class GeneralHelper
     {
         public static bool IsWindows = RuntimeInformation.IsOSPlatform(OSPlatform.Windows);
+        /// <summary>
+        /// returns true for android too.
+        /// </summary>
         public static bool IsLinux = RuntimeInformation.IsOSPlatform(OSPlatform.Linux);
         public static string WindowsLibsPath = Path.Combine(AppContext.BaseDirectory, "WindowsLibs");