Disable SetupRedactionInterstitial when complete

When RedactionInterstitial is complete, there is no need to show the
SetupRedactionInterstitial as optional step anymore. Disable it via
package manager when RedactionInterstatial completes.

Test: Manual
Bug: 36696006
Change-Id: I3fd421d6a8a0d24d7ebbe8c1e688a10e00067f2f