GPII-247: Adding startActivityByPackageName method

This method can be used as a lifecycleManager action in order to launch
applications, identified by a well-known packageName.

To use this method for starting applications, your lifecycleManager
action block should look like it follows:

"lifecycleManager": {
    "start": [
        {
            "type": "gpii.androidActivityManager.startActivityByPackageName",
            "packageName": "com.package.name"
        }
    ]
}
GPII-247: Adding stopActivityByPackageName method

This method can be used as a lifecycleManager action in order to
stop applications, identified by a well-known packageName.

To use this method for stoping applications, your lifecycleManager
action block should look like it follows:

"lifecycleManager": {
    "stop": [
        {
            "type": "gpii.androidActivityManager.stopActivityByPackageName",
            "packageName": "com.package.name"
        }
    ]
}
GPII-247: Adding goToHomeScreen method

With this method we're adding a mechanism to get the user to the home
screen.
Merge remote-tracking branch 'javihernandez/GPII-247_II'