examples: Add XDS client example

diff --git a/examples/example-xds/settings.gradle b/examples/example-xds/settings.gradle
new file mode 100644
index 0000000..9f46a95
--- /dev/null
+++ b/examples/example-xds/settings.gradle
@@ -0,0 +1,3 @@
+rootProject.name = 'example-xds'
+
+includeBuild '..'