Revert "[ar] Do not refer to ARCore shim in APK merger"

This reverts commit 58e4a081ad03d83758dcbbad2fda09417baabf61.

Reason for revert: appears to be still required.

Original change's description:
> [ar] Do not refer to ARCore shim in APK merger
> 
> This hard-coding should no longer be required.
> 
> Bug: 839191
> Change-Id: Id44f0f19da6efcee90ef79ea3e241eb2a7ea5843
> Reviewed-on: https://chromium-review.googlesource.com/1147706
> Commit-Queue: Ian Vollick <vollick@chromium.org>
> Reviewed-by: Richard Coles <torne@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#577662}

TBR=vollick@chromium.org,torne@chromium.org

Change-Id: Ia4e5bd3908b40e5cbcff058230cad20542c57a31
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 839191
Reviewed-on: https://chromium-review.googlesource.com/1150120
Reviewed-by: Ian Vollick <vollick@chromium.org>
Commit-Queue: Ian Vollick <vollick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#577845}
2 files changed