Build with Mono.Android api 26

This is really used only for type resolution for merging assemblies, but we don’t have api 27 support yet for Mono.Android 27, so stick with 26 for now.

Author: Redth

build.cake

@@ -27,7 +27,7 @@ var ARCH_CORE_PKG_NAME = "android.arch.core";
 // FROM: https://dl.google.com/android/repository/addon2-1.xml
 var MAVEN_REPO_URL = "https://dl.google.com/dl/android/maven2/";
 var BUILD_TOOLS_URL = "https://dl-ssl.google.com/android/repository/build-tools_r27-macosx.zip";
-var ANDROID_SDK_VERSION = IsRunningOnWindows () ? "v8.1" : "android-27";
+var ANDROID_SDK_VERSION = IsRunningOnWindows () ? "v8.0" : "android-26";
 var RENDERSCRIPT_FOLDER = "android-8.1.0";
 var REFERENCE_DOCS_URL = "https://developer.android.com/reference/";
 var REFERENCE_DOCS_PACKAGELIST_URL = REFERENCE_DOCS_URL + "android/support/package-list";