Revert "Expose getSpi from crypto operations as hidden API."
This reverts commit 050e672a.
The users of public getSpi have been migrated to getCurrentSpi
introduced in 5d15925a.
(cherry-picked from commit c52bf74f)
Bug: 18088752
Change-Id: Ied72c8a62a49d9fba8b7bc2d3ef2e30da7daa6e4