Add a snapshot of flutter/engine/src/build to our sdk

build/android/gyp/test/BUILD.gn

Index: build/android/gyp/test/BUILD.gn
diff --git a/build/android/gyp/test/BUILD.gn b/build/android/gyp/test/BUILD.gn
new file mode 100644
index 0000000000000000000000000000000000000000..2deac1d56f2318caab038783635cb2a84f723c2e
--- /dev/null
+++ b/build/android/gyp/test/BUILD.gn
@@ -0,0 +1,13 @@
+import("//build/config/android/rules.gni")
+
+java_library("hello_world_java") {
+  java_files = [ "java/org/chromium/helloworld/HelloWorldPrinter.java" ]
+}
+
+java_binary("hello_world") {
+  deps = [
+    ":hello_world_java",
+  ]
+  java_files = [ "java/org/chromium/helloworld/HelloWorldMain.java" ]
+  main_class = "org.chromium.helloworld.HelloWorldMain"
+}