bitbake: toaster: orm generate CustomImageRecipe contents try secondary path

bitbake: toaster: orm generate CustomImageRecipe contents try secondary path

Try a secondary file path if the first does not exist. When we get the
recipe paths and layer information from the layer index it is not a
complete path but we are usually able to reconstruct it. If the complete
real path has been discovered by building then use this instead.

[YOCTO #9206]

(Bitbake rev: 238db2e03405d259d48dfc477a276191e6a47698)

Signed-off-by: Michael Wood <michael.g.wood@intel.com>
Signed-off-by: Elliot Smith <elliot.smith@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>