Update Stocks.apk build tech

sky/sdk/README.md

 Contributing
 ============
 
 [sky_sdk](https://github.com/domokit/sky_sdk) is generated from the
 [mojo repository](https://github.com/domokit/mojo) using
 [deploy_sdk.py](https://github.com/domokit/mojo/blob/master/sky/tools/deploy_sdk.py)
 Static files (including this README.md) are located under
 [sky/sdk](https://github.com/domokit/mojo/tree/master/sky/sdk).  Pull
 requests and issue reports are glady accepted at the
 [mojo repository](https://github.com/domokit/mojo)!
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 debugging and profiling. While running your Sky app using `sky_tool`, you can
 access Observatory by navigating your web browser to http://localhost:8181/.
 
 Building a standalone MyApp
 ---------------------------
 
 Although it is possible to bundle the Sky Engine in your own app (instead of
 running your code inside SkyDemo.apk), right now doing so is difficult.
 
 There is one example of doing so if you're feeling brave:
-https://github.com/domokit/mojo/tree/master/sky/apk/stocks
+https://github.com/domokit/mojo/tree/master/sky/sdk/example/stocks
 
 Eventually we plan to make this much easier and support platforms other than
 Android, but that work is yet in progress.
 
 Adding Services to MyApp
 ------------------------
 
 [Mojo IPC](https://github.com/domokit/mojo) is an inter-process-communication
 system designed to provide cross-thread, cross-process, and language-agnostic
 communication between applications.  Sky uses Mojo IPC to make it possible
 to write UI code in Dart and yet depend on networking code, etc. written in
 another language.  Services are replicable, meaning that Dart code
 written to use the `network_service` remains portable to any platform
 (iOS, Android, etc.) by simply providing a 'natively' written `network_service`.
 
 Embedders of the Sky Engine and consumers of the Sky Framework can use this
 same mechanism to expose not only existing services like the
 [Keyboard](https://github.com/domokit/mojo/blob/master/mojo/services/keyboard/public/interfaces/keyboard.mojom)
 service to allow Sky Framework Dart code to interface with the underlying
 platform's Keyboard, but also to expose any additional non-Dart business logic
 to Sky/Dart UI code.
 
 As an example, [SkyApplication](https://github.com/domokit/mojo/blob/master/sky/shell/org/domokit/sky/shell/SkyApplication.java)
 exposes a mojo `network_service` (required by Sky Engine C++ code)
 [SkyDemoApplication](https://github.com/domokit/mojo/blob/master/sky/apk/demo/org/domokit/sky/demo/SkyDemoApplication.java)
 additionally exposes `keyboard_service` and `sensor_service` for use by the Sky
 Framework from Dart.