Added note in Android doc on host config (#2049)

solutions/android/VirtualAssistantClient/readme.md

@@ -18,9 +18,7 @@
 - [Create a Speech Cognitive Service Key](https://github.com/microsoft/botframework-solutions/blob/master/docs/howto/assistant/csharp/speechenablement.md#create-a-microsoft-speech-instance)
 - [Add the Speech Channel to your assistant](https://github.com/microsoft/botframework-solutions/blob/master/docs/howto/assistant/csharp/speechenablement.md#add-the-speech-channel-to-your-assistant)
 
-
-
-### Step 1 - Credentials
+### Step 1 - Apply Credentials
 
 Edit `DefaultConfiguration.java` to provide the *SPEECH_SERVICE_SUBSCRIPTION_KEY*, *DIRECT_LINE_SPEECH_SECRET_KEY* and *USER_FROM_ID* which will be used to perform speech operations and identify the user uniquely. 
 
@@ -29,7 +27,11 @@ Edit `DefaultConfiguration.java` to provide the *SPEECH_SERVICE_SUBSCRIPTION_KEY
 
 The USER_FROM_ID is a unique identifier for all messages generated by the user, this is typically combined with [Linked Accounts](https://github.com/microsoft/botframework-solutions/blob/master/docs/howto/assistant/linkedaccounts.md).
 
-### Step 2 - Deploy
+### Step 2 - Customize the styling
+You can control the basic styling and behavior of Adaptive Cards by providing your own [HostConfig](https://docs.microsoft.com/en-us/adaptive-cards/rendering-cards/host-config) file.
+Replace the provided [hostconfig.json file](/VirtualAssistantClient/app/src/main/res/raw/hostconfig.json) with your own.
+
+### Step 3 - Deploy
 1. Select the desired build flavor (debug or release) and ensure credentials are set for the desired build flavor
 2. Deploy to emulator or device