ActivityManager: Warning: Activity not started, its current task has been brought to the front
You get this warning when you run your app either on android emulator or device if you have made no changes to the project code and you try to run the app which is already running i.e. brought in front.
The compiled .apk file is installed to the device or emulator only when some charges are made to the project.
To get rid of this warning simply exit the app from device and run it the project again.