[Android] Unified xenia-app with windowed apps and build prerequisites

tools/build/scripts/single_library.lua

@@ -0,0 +1,20 @@
+SINGLE_LIBRARY_PLATFORM_PATTERNS = {
+    "Android-*",
+};
+
+SINGLE_LIBRARY_FILTER =
+    "platforms:" .. table.concat(SINGLE_LIBRARY_PLATFORM_PATTERNS, " or ");
+NOT_SINGLE_LIBRARY_FILTER = table.translate(
+    SINGLE_LIBRARY_PLATFORM_PATTERNS,
+    function(pattern)
+      return "platforms:not " .. pattern;
+    end);
+
+function single_library_windowed_app_kind()
+  filter(SINGLE_LIBRARY_FILTER);
+    kind("StaticLib");
+    wholelib("On");
+  filter(NOT_SINGLE_LIBRARY_FILTER);
+    kind("WindowedApp");
+  filter({});
+end