Merge "Update D8 and R8 to 8.3.20-dev" into main am: 7d88d6aabb am: 1286fbc272

Original change: https://android-review.googlesource.com/c/platform/prebuilts/r8/+/2849715

Change-Id: Ia9e69c09ec089d241b721b1d3cee780227b76cd2
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>