Remove SearchIndexProvider from DataPlanUsageSummary fragment.

This change will prevent showing Data plan usage in the settings search.
Data plan usage feature has been punted to next release and we do not
want to show this to user in current release.

Bug: 68022715
Test: make RunSettingsRoboTests -j40
Change-Id: I56b71796e3c426122434ca9e86c1a2db691849cf
DO NOT MERGE
(cherry picked from commit dd8e66fa)