Show correct drop targets for All-apps predicted item drags.

This change fixes a bug where, after a user drags and drops a
predicted app from the all apps page once, dragging that item again
results in the "Remove" drop target being shown rather than the
"Do Not Suggest" drop target.

Bug: 221057278
Test: Verified correct drop down targets were present after fix when
dropping all apps prediction item on workspace multiple times in a row.

Change-Id: I95940eeebbd547861fcdfbb5d02769b82446184d