Update D8 R8 to 8.4.6-dev am: 27a87892b5 am: a92fc04652

Original change: https://android-review.googlesource.com/c/platform/prebuilts/r8/+/2901968

Change-Id: I43f0f687cb4986d123de4238e0a2b279fbc13eba
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>