Fixing GMSCore version incompatibility

Calling GMSCore's isGooglePlayServicesAvailable(context) uses our SDK to
check what corresponding version of the GMSCore app we need on the
device. This assumption (that we need the GMSCore app to be ahead of the
SDK) hasn't been true for years for most Google apps, and that
requirement is breaking us when we update to bleeding-edge GMSCore SDKs.

This is currently blocking new users from signing into Canary.

Testing: Was able to reproduce error message with local build:
https://photos.app.goo.gl/e9PJ9cmhRaeH7THt6
With this change, error message did not appear, and signin button was
not greyed out. This is consistent with another local build made before
the breaking roll occurred.

TBR: nyquist, mattreynolds, bsazonov for urgent refactor
Bug: 1144669, 1145211
Change-Id: Iea18fc7340222bbf6027e210318cca6c68105a4c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2518219
Commit-Queue: Sam Maier <smaier@chromium.org>
Reviewed-by: Boris Sazonov <bsazonov@chromium.org>
Reviewed-by: Reilly Grant <reillyg@chromium.org>
Reviewed-by: Theresa  <twellington@chromium.org>
Cr-Commit-Position: refs/heads/master@{#824035}