Update README.md (#84)

Update the sample preset name to be the correct one.

Author: eladrkatz

sample/README.md

@@ -11,7 +11,7 @@ Once you clone this repository there are two required steps to build the sample
 2. Create an upload preset named 'sample_app_preset' in your cloudinary account console:
     *  Login to your [Cloudinary console](https://cloudinary.com/console), go to settings>upload, scroll down
       to Upload Presets and click `Add upload preset`. Alternatively, head directly to the [new preset page](https://cloudinary.com/console/lui/upload_presets/new).
-    * Type in `sample_app_preset` as the name and save, leaving all the fields with their default values.
+    * Type in `android_sample` as the name and save, leaving all the fields with their default values.
 
 After completing the steps above the sample app should be ready to be deployed and upload resource to your Cloudinary cloud.