meta-google: layer.conf: Add warrior compatibility

oe-core branched in preparation for the upcoming 2.7 Yocto release and
as of 13e45ff requires core layer compatibility to "warrior" instead of
"thud".  We'll retain compatibility for both until we do our own branch
or stop testing thud.

(From meta-google rev: 2282c02ed2b9021205840e6bd9b3fdcf70870f87)

Signed-off-by: Patrick Venture <venture@google.com>
Change-Id: I9396d0ec3ea4fbbb9a8ba5aaa685196f7a087dd3
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/meta-google/conf/layer.conf b/meta-google/conf/layer.conf
index 0f4bd15..b446ef0 100644
--- a/meta-google/conf/layer.conf
+++ b/meta-google/conf/layer.conf
@@ -7,4 +7,4 @@
 BBFILE_COLLECTIONS += "google-layer"
 BBFILE_PATTERN_google-layer = ""
 LAYERVERSION_google-layer = "1"
-LAYERSERIES_COMPAT_google-layer = "thud"
+LAYERSERIES_COMPAT_google-layer = "thud warrior"