Update D8 and R8 to 2.1.6-dev

Version: master 2.1.6-dev
This build IS NOT suitable for preview or public release.

Built here: go/r8-releases/raw/2.1.6-dev

Test: TARGET_PRODUCT=aosp_arm64 m -j core-oj
Change-Id: Iab210ad761b36bf12bb21621754a78a0bec239d0
2 files changed