conf/layer.conf: Rename browser-layer as chromium-browser-layer
This commit updates the directory name of the browser-layer
dynamic-layer because the changes introduced in
https://github.com/OSSystems/meta-browser/pull/470. This browser-layer
doesn't exist anymore in the meta-browser layer being replaced by a new
chromium-browser-layer.
For backwards compatibility this changes keeps the entries associated to
the former browser-layer pointing to the new chromium-browser-layer.
Signed-off-by: Pablo Saavedra <psaavedra@igalia.com>
