- Adds 3x resources to components/resources/autofill. These missing
  resources where causing the ResourceBundle to load the 1x ones for
  iPhone plus devices which resulted in blurry icons.
- Modifies the 1x and 2x resources for the generic credit card to match
  the 3x one.
- Removes the imagesets from iOS bundle and changes the autofill suggestion
  code to use the resources in the components.

Bug: 763499
Change-Id: I5463bc20c30b884ee4685a3fd2cd28d84625a709
Reviewed-on: https://chromium-review.googlesource.com/660802
Commit-Queue: Moe Ahmadi <mahmadi@chromium.org>
Reviewed-by: Sylvain Defresne <sdefresne@chromium.org>
Cr-Commit-Position: refs/heads/master@{#501283}