Revert "Derive FastStringSearchResource from ResourceData, not SweepableResourceData"

This reverts commit 2dfac3e284dabbc8d5001ae1bda32c5ddbc07d17.

Change-Id: Icf5e59593478c85be9058fadce8dce76aedfe76e
Fixes per CR on github

Change-Id: I3f3b9976db05695aab3b21f34f1886aa342f03c8