Revert "Update D8 and R8 to 2.1.28-dev" am: 8c78bf7a7f am: 996df75b9b am: 285152a229

Original change: https://android-review.googlesource.com/c/platform/prebuilts/r8/+/1343838

Change-Id: I48ba4dab83fce4f6626e0f2642f42f3cad273ad1