Create GitHub workflow for validating Dockerfiles

.github/workflows/on-demand_docker.yml

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+---
+# Copyright 2022 Samsung Corporation
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+name: Check Docker files
+# yamllint disable-line rule:truthy
+on: 
+  push:
+    branches:
+      - master
+    paths:
+      - '**/Dockerfile'
+  pull_request:
+    branches:
+      - master
+    paths:
+      - '**/Dockerfile'
+
+jobs:
+  check-dockerfile-lint:
+    name: Check Dockerfile lint issues (hadolint)
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: hadolint/[email protected]
+        with:
+          recursive: true