Add missing cases where empty suggestions should be sent to IME.

1. When regular autofill returned null and augmented autofill is
disabled by password. (regular disabled augmented autofill case is
handled by session being destroyed).
2. If the response contains empty/null datasets or service disabled
autofill when response is received by frameworks.

Bug: 159364411
Test: atest InlineLoginActivityTest
Change-Id: Ic0758e757eacd277a5bf43080fe4db82d603953e