[DO NOT MERGE] Improve the error msg when started not for result

This makes sure that if the association request callback IntentResult
s accidentally started not for result, the resulting exception is
metioning it explicitly.

Test: Ensure the error message when calling the IntentSender not for result
  explicitly mentions the requirement for the activity to be called for result.
Bug: 30932767

Change-Id: I950f262af43c555fb20dd5e49e935e476f24bba8
1 file changed