Optionally schedule a delayed deletion of suggestions in sample keyboard am: 1bbbbac30e am: 14ce26727a am: 1263bb7e4f am: d099043a5e

Original change: https://googleplex-android-review.googlesource.com/c/platform/development/+/11921811

Change-Id: I0cb75f14f7caaf4bf70c03860d70a36c657e09cb