Adding the Activity for ClearData intent from ag/1806300

This exposes the activity of the Intent to show the user a
confirmation AlertDialog before clearing a package's data.

Test: Covered by a gts-test ag/1806256 and manually tested
by calling from com.google.vending (Play Store).

bug: 33017941
bug: 31008483

Change-Id: I3199cdb5846c1f99448f543e0edf082d09e6f420