[Data Sharing] Use Chrome border for SharedImageTiles

Change to use Chrome component provided border. This unifies all border and background definition to round_image_filled.xml for consistency and remove the need to pass duplicated dimens and colors to PeopleKit.

https://screenshot.googleplex.com/5jJgz4Z3SiDj9Ji.png

Change-Id: Id39725ffd5d959bc21db90f6bb7fa33f2d7acc2e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5887587
Reviewed-by: Salvador Guerrero Ramos <salg@google.com>
Commit-Queue: Hailey Wang <haileywang@google.com>
Cr-Commit-Position: refs/heads/main@{#1371593}