Fix NPE when using HttpClient from online Android application

android/src/main/java/com/genexus/Application.java

@@ -250,6 +250,9 @@ public static boolean hasClientPreferences()
 	*/
 	public static ClientPreferences getClientPreferences()
 	{
+		if (!hasClientPreferences())
+			return null;
+
 		return (ClientPreferences) ((ModelContext)ClientContext.getModelContext()).getPreferences();
 	}
 

android/src/main/java/com/genexus/specific/android/Application.java

@@ -24,7 +24,15 @@ public void exit() {
 
 	@Override
 	public Object getProperty(String key, String defaultValue) {
-		return com.genexus.Application.getClientContext().getClientPreferences().getProperty(key, defaultValue);
+		com.genexus.ModelContext modelContext = com.genexus.Application.getClientContext();
+		if (modelContext == null)
+			return defaultValue;
+
+		IClientPreferences preferences = modelContext.getClientPreferences();
+		if (preferences == null)
+			return defaultValue;
+
+		return preferences.getProperty(key, defaultValue);
 	}
 
 	@Override

android/src/main/java/com/genexus/specific/android/HttpClient.java

@@ -19,7 +19,11 @@ public class HttpClient implements IExtensionHttpClient {
 
 	@Override
 	public void addSDHeaders(String host, String baseURL, Hashtable<String, String> headersToSend) {
-		com.genexus.Preferences.getDefaultPreferences().getProperty("USER_LOG_NAMESPACE", "GeneXusUserLog");
+		com.genexus.Preferences preferences = com.genexus.Preferences.getDefaultPreferences();
+		if (preferences == null)
+			return;
+
+		preferences.getProperty("USER_LOG_NAMESPACE", "GeneXusUserLog");
 	}
 
 	@Override