Add ANDROID_SDK_VERSION CXX definition

Author: colemancda

Package.swift

@@ -398,6 +398,10 @@ var package = Package(
         ),
         .target(
             name: "AndroidNDK",
+            cxxSettings: [
+                .define("ANDROID_NDK_VERSION", to: ndkVersion.description),
+                .define("ANDROID_SDK_VERSION", to: sdkVersion.description)
+            ],
             linkerSettings: [
                 .linkedLibrary("android", .when(platforms: [.android]))
             ]