[Docs] Update docs with setDeploymentKey method (#1117)

Author: ruslan-bikkinin

docs/api-android.md

@@ -47,6 +47,10 @@ As an alternative to constructors *you can also use `CodePushBuilder`* to setup
 
 * __public CodePush build()__ - return configured `CodePush` instance.
 
+##### Public Methods
+
+- __setDeploymentKey(String deploymentKey)__ - Sets the deployment key that the app should use when querying for updates. This is a dynamic alternative to setting the deployment key in Codepush constructor/builder and/or specifying a deployment key in JS when calling `checkForUpdate` or `sync`.
+
 ##### Static Methods
 
 - __getBundleUrl()__ - Returns the path to the most recent version of your app's JS bundle file, assuming that the resource name is `index.android.bundle`. If your app is using a different bundle name, then use the overloaded version of this method which allows specifying it. This method has the same resolution behavior as the Objective-C equivalent described above.