gitlab-ci: set a common job parent for container stage

While at it, rename to singular "container" for consistency.

Signed-off-by: Eric Engestrom <eric.engestrom@intel.com>
Reviewed-by: Michel Dänzer <mdaenzer@redhat.com>
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 3fa11e1..7c9b82c 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -32,7 +32,7 @@
   - local: '/.gitlab-ci/lava-gitlab-ci.yml'
 
 stages:
-  - containers
+  - container
   - build
   - test
 
@@ -59,13 +59,19 @@
 
 # Build the normal CI native and cross-build docker images.
 
+.container:
+  stage: container
+  extends:
+    - .ci-run-policy
+  variables:
+    # no need to pull the whole repo to build the container image
+    GIT_STRATEGY: none
+
 debian-10:
   extends:
     - .debian@container-ifnot-exists
-    - .ci-run-policy
-  stage: containers
+    - .container
   variables:
-    GIT_STRATEGY: none # no need to pull the whole tree for rebuilding the image
     DEBIAN_EXEC: 'bash .gitlab-ci/debian-install.sh'
 
 .use-debian-10:
@@ -91,13 +97,12 @@
 test-container:arm64:
   extends:
     - .debian@container-ifnot-exists@arm64v8
-    - .ci-run-policy
-  stage: containers
+    - .container
   variables:
     DEBIAN_TAG: "$DEBIAN_ARM64_TAG"
-    GIT_STRATEGY: none # no need to pull the whole tree for rebuilding the image
     DEBIAN_EXEC: 'bash .gitlab-ci/debian-test-install.sh'
 
+
 # BUILD
 
 .build:
diff --git a/.gitlab-ci/lava-gitlab-ci.yml b/.gitlab-ci/lava-gitlab-ci.yml
index a35a724..bcf4591 100644
--- a/.gitlab-ci/lava-gitlab-ci.yml
+++ b/.gitlab-ci/lava-gitlab-ci.yml
@@ -22,10 +22,8 @@
 .lava-container:
   extends:
     - .debian@container-ifnot-exists
-    - .ci-run-policy
-  stage: containers
+    - .container
   variables:
-    GIT_STRATEGY: none # no need to pull the whole tree for rebuilding the image
     DEBIAN_TAG: '${DEBIAN_ARCH}-${LAVA_IMAGE_TAG}'
     DEBIAN_EXEC: 'DEBIAN_ARCH=${DEBIAN_ARCH}
                   GCC_ARCH=${GCC_ARCH}