When finding a compatible memory index for an external buffer,
we need to have a fallback path that requires just the
VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT property.

Bug: angleproject:5909
Change-Id: Id3faffb3e357be2e5e6f5fce9e64f0f2889d199a
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2862561Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>
Commit-Queue: Mohan Maiya <m.maiya@samsung.com>