Revert "[Cros SR] Add training for Arc App Shorcuts"

This reverts commit 8fc6db2431405777d4c300b5741e0540d5120e6d.

Reason for revert: https://crbug.com/935122

Original change's description:
> [Cros SR] Add training for Arc App Shorcuts
> 
> See here for context:
> 
>   https://docs.google.com/document/d/1GTQ3vvrszK4I1pDzmTFb6krmUzAXox0V9ZIqIi_GH1E/edit?usp=sharing
> 
> We are expanding Roselle to re-rank the results returned when the user enters
> a query. However, these results include Arc app shortcuts as well as apps
> themselves, so they need to be ranked. This CL adds the training support for
> Arc App Shortcuts and use Roselle score to update current relevance score.
> 
> Bug: 931149
> Change-Id: I979ebd500504681c9b0c0e59aa0412b4cbd47315
> Reviewed-on: https://chromium-review.googlesource.com/c/1481176
> Commit-Queue: Thanh Nguyen <thanhdng@chromium.org>
> Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
> Reviewed-by: Jia Meng <jiameng@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#634881}

TBR=xiyuan@chromium.org,jiameng@chromium.org,thanhdng@chromium.org

Change-Id: I9846f900136f23578ee0bb67cc4761c22cff5b3b
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 931149
Reviewed-on: https://chromium-review.googlesource.com/c/1485057
Reviewed-by: Nico Weber <thakis@chromium.org>
Commit-Queue: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#634976}
3 files changed