fixup! Add test cases for implicit container contribution feature

Author: AObuchow

pkg/library/flatten/testdata/implicit-container-contributions/opt-in-non-first-component.yaml

@@ -0,0 +1,88 @@
+name: "Opt in for second component"
+
+input:
+  devworkspace:
+    components:
+      - name: test-component
+        container:
+          image: test-image
+          env:
+            - name: TEST_ENVVAR
+              value: TEST_VALUE
+      - name: test-component-opt-in
+        attributes:
+          controller.devfile.io/merge-contribution: true
+        container:
+          image: test-image
+          env:
+            - name: TEST_ENVVAR
+              value: TEST_VALUE
+
+      - name: test-contribution
+        plugin:
+          uri: test-contribution.yaml
+
+  devfileResources:
+    test-contribution.yaml:
+      schemaVersion: 2.1.0
+      metadata:
+        name: test-contribution
+      components:
+      - name: test-contribution
+        attributes:
+          controller.devfile.io/container-contribution: true
+        container:
+          image: contribution-image
+          env:
+            - name: CONTRIB_ENVVAR
+              value: CONTRIB_VALUE
+      - name: unmerged-container
+        container:
+          image: unmerged-container
+      - name: unmerged-volume
+        volume: {}
+      commands:
+      - name: plugin-command
+        apply:
+          component: unmerged-container
+      events:
+        prestart:
+          - plugin-command
+
+output:
+  devworkspace:
+    components:
+      - name: test-component
+        container:
+          image: test-image
+          env:
+            - name: TEST_ENVVAR
+              value: TEST_VALUE
+      - name: test-component-opt-in
+        attributes:
+          controller.devfile.io/merged-contributions: "test-contribution"
+        container:
+          image: test-image
+          env:
+            - name: TEST_ENVVAR
+              value: TEST_VALUE
+            - name: CONTRIB_ENVVAR
+              value: CONTRIB_VALUE
+      - name: unmerged-container
+        attributes:
+          controller.devfile.io/imported-by: test-contribution
+        container:
+          image: unmerged-container
+      - name: unmerged-volume
+        attributes:
+          controller.devfile.io/imported-by: test-contribution
+        volume: {}
+    commands:
+      - name: plugin-command
+        attributes:
+          controller.devfile.io/imported-by: test-contribution
+        apply:
+          component: unmerged-container
+    events:
+        prestart:
+          - plugin-command