AF: Remove the timeout for receiving InlineSuggestionsRequest from IME

There are a few things the timeout was protecting against:
* IME taking too long to come up or failing to come up entirely - in
  this case, the user cannot enter text anyway, so the incremental
  degradation in UX from autofill not showing either is relatively
  minimal.
* IME taking too long to send back the InlineSuggestionsRequest - this
  would happen if the IME implementation is suboptimal. There's a valid
  case for protecting against this, however there are many other ways
  the IME can prevent Autofill from working correctly (e.g. just not
  showing the chips) that we do not have a fallback for - so introducing
  a fallback for just one of these cases doesn't seem worth the added
  complexity.

Note: There doesn't seem to be any cleanup the timeout was doing that
needs to be handled.

Test: manual:
* switching focused view multiple times, also with a Thread.sleep(7000)
  in the keyboard to make sure a delayed response works fine, also
  tested with multiple partitions.
* smart reply, including clicking through from a notification
* interrupting pending request with manual request
Test: atest InlineAugmentedLoginActivityTest InlineLoginActivityTest \
  AugmentedLoginActivityTest LoginActivityTest
Fixes: 154334419

Change-Id: Id934fe3be991b5d70e9e8cb3e37b0fd869d783b7