Add workflow for running and reporting checkstyle.

.github/workflows/generic.checkstyle.yml

@@ -0,0 +1,18 @@
+name: 'Generic: Checkstyle'
+
+on:
+  workflow_call:
+
+jobs:
+  checkstyle:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+    steps:
+      - uses: actions/checkout@v3
+
+      - uses: dbelyaev/action-checkstyle@v0.8.4
+        with:
+          github_token: ${{ secrets.GITHUB_TOKEN }}
+          checkstyle_version: 10.12.2
+          checkstyle_config: ./config/mv_checks.yml

.github/workflows/pr.checkstyle.yml

@@ -0,0 +1,9 @@
+name: 'PR: Checkstyle'
+
+on:
+  pull_request:
+    types: [opened, synchronize]
+
+jobs:
+  test:
+    uses: ./.github/workflows/generic.checkstyle.yml