Revert "Update D8 and R8 to 1.7.16-dev"

This reverts commit 355d830ee3e27885bc30dde9e0b68a5a1b9a97e0.

Reason for revert: broke pixel launcher b/143469612

Change-Id: Ie7d6ef846aa7a35245485fd2403f800d8ffd9f90
6 files changed