Update D8 and R8 to 8.3.21-dev am: f41676e361

Original change: https://android-review.googlesource.com/c/platform/prebuilts/r8/+/2856147

Change-Id: I40c29c24d19c32f8e65a88d31e32ff49557eeb27
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>