anv/android: support creating images from external format

anv/android: support creating images from external format

Since we don't know the exact format at creation time, some initialization
is done only when bound with memory in vkBindImageMemory.

v2: demand dedicated allocation in vkGetImageMemoryRequirements2 if
    image has external format

v3: refactor prepare_ahw_image, support vkBindImageMemory2,
    calculate stride correctly for rgb(x) surfaces, rename as
    'resolve_ahw_image'

v4: rebase to b43f955037c changes
v5: add some assertions to verify input correctness (Lionel)

Signed-off-by: Tapani Pälli <tapani.palli@intel.com>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>