Check DPC package validity during package updates

Bug: 384514657
Bug: 414603411
Test: manual
Flag: EXEMPT bugfix
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:10df9cf5572d9e7f568b9aa821c14bdbd6bbd0d2)
Merged-In: I1743c111f8e8b5f4c1f878a61b88b8f1ed6b86a1
Change-Id: I1743c111f8e8b5f4c1f878a61b88b8f1ed6b86a1