get Fallback Intent
Called as a fallback when a previous task stack builder or intent could not be launched. By default, use the getLaunchIntentForPackage method to get an intent. If null is returned, the action is ignored.
Recommended: use this method when you want to customise the default intent for your app. (not launching the LAUNCHER activity of your manifest for example)
Return
The intent to launch
Parameters
context
The current context