Points To Remember

Android saves the Application level Settings like App Icon, App Label etc in the AndroidManifest.xml file.

How to change the Android Application Icon 

Go to the Application > manifests > AndroidManifests.xml file and look for the following lines.

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.ekiras.activity" >

<application
android:allowBackup="true"
android:icon="@drawable/icon"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
// Your activities are declared here
<activity></activity>
</application>

</manifest>

You can set the Application icon in strings.xml by name app_name in the values folder.

<resources>
<string name="app_name">Ekiras</string>
<string name="action_settings">Settings</string>
</resources>

If you do not want to keep them in strings.xml file then you can simple assign them in AndroidManifests.xml file , however it is recommended that you keep them in strings.xml file.