ZenDesk 3537 Revise online doc: App Icon Replacement for Android

[amyng95132]

In order to replace the default Rho icon with customer's icon, all the default .png files has to be replaced with the customized icons before compiling the apk.

However, this is what the customer found from our online doc:
Android
You can change the icon for your Android application by replacing icon.png, which is in your application icon folder, with a new icon.png."

Please refer to the link below and scroll down to the "Android" section:
http://docs.rhomobile.com/en/5.1.1/guide/app_icon_splash

Note: Application icon doesn’t change when ONLY the icon.png is replaced. All the default .png files has to be replaced with the customized icons.