Fix the bug to not request IME twice for augmented autofill only field

* Before the fix, we may ask IME for inline request for the augmented
  autofill only case twice in case of first starting the session.
* Now the standard autofill only asks IME for inline request before
  requesting the assist structure data.

Test: atest CtsAutoFillServiceTestCases
Bug: 153086411

Change-Id: If7311744a5acb7d87673320570bcd91c7f040202