Drop PendingIntent extras from external packages during enrollment.

Bug: 388528350
Flag: EXEMPT bugfix
Test: atest FingerprintEnrollIntroductionTest FaceEnrollIntroductionTest
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:4ccdeee849d5fef78498ba33cadc525523efcbd7)
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:638757a3001417a211ba3b72ffc43b6c751437b1)
Merged-In: I61281dcf95e53100a96d6a218f3f00fd1b4ea3f9
Change-Id: I61281dcf95e53100a96d6a218f3f00fd1b4ea3f9