The address of each attribute in a vertex buffer must be aligned
according to its format. See section 20.3 of vkspec.

Currently we don't handle this when using DynamicBuffer as vertex
input buffer. This loosely fixes the issue by using max alignment for
all formats.

BUG=angleproject:2797,angleproject:2405

Change-Id: I2b27950dacc8fda75dcb646ef4b4d66ff27d629a
Reviewed-on: https://chromium-review.googlesource.com/1234281
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>