Revert "[ADI][7/N] only the current verifier can call VerificationSession APIs"

FLAG: EXEMPT just revert
BUG: 422535876
Test: n/a just revert

This reverts commit e894177d.
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:686515469ce447882591fec6e9ee161f119da0c2)
Merged-In: I3bd0ab593f98868a7afab9949ba7989334b3dfcc
Change-Id: I3bd0ab593f98868a7afab9949ba7989334b3dfcc