ATOM-15908 Fixed material component exporter to use correct relative paths
* Final update copyright headers to reference license files at the repo root Signed-off-by: spham <spham@amazon.com> * Fix copyright validator unit tests to support the stale O3DE header scenario Signed-off-by: spham <spham@amazon.com>
Signed-off-by: guthadam <guthadam@amazon.com>