Revert "Update D8 R8 to 8.5.6-dev"

This reverts commit 70b934963fa8b96da35f22fa6800b993debc86ef.

Reason for revert: Culprit of b/335777227

Change-Id: I3d07d4336748409348211c5c80e7638347dd0a69
4 files changed