[automerger skipped] [automerge] [DO NOT MERGE]Revert "Relax minimum signature scheme version for apps on system partition" 2p: 3c36fd5f am: 659d441a -s ours

am skip reason: subject contains skip directive

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/16943318

Change-Id: I266a49032c34f999e451f4de2c6fe2ae5db46861