Correct how the injection mechanism starts activities

Settings Injection used to start activities with
startActivityForResult() and its extension, where there was not result
really being handled. Hence, this CL corrects the way it starts
activities by removing the "ForResult" part.

Fixes: 197704126
Test: robotest and launch Android Auto to see it being launched in
another task.

Change-Id: I259b2555cf62f8966afdf664b337af5f216b3843