layers: Install into the data root directory
layers: Install into the data root directory

The layers files fit are not really configuration files and are rarely
edited by users. So, let's move the install location into the
data root directory.

Signed-off-by: Nick Sarnie <4794d360835f5295e9d62d811e5f88b551d0efd6@gentoo.org>

KhronosGroup/Vulkan-Tools,KhronosGroup/Vulkan-Tools,KhronosGroup/Vulkan-Tools,KhronosGroup/Vulkan-Tools