include release note to CHANGELOG

Author: jinliu9508

.github/workflows/create-release-pr.yml

@@ -128,4 +128,33 @@ jobs:
       android_from: ${{ needs.update-version.outputs.android_from }}
       android_to: ${{ inputs.android_version }}
       ios_from: ${{ needs.update-version.outputs.ios_from }}
-      ios_to: ${{ inputs.ios_version }}
+      ios_to: ${{ inputs.ios_version }}
+
+  update-changelog:
+    needs: [create-pr]
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v5
+        with:
+          ref: ${{ needs.prep.outputs.release_branch }}
+
+      - name: Get PR release notes
+        id: notes
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          sudo apt-get update && sudo apt-get install -y gh || true
+          PR_NUMBER=$(gh pr list --head "${{ needs.prep.outputs.release_branch }}" --json number -q '.[0].number' || echo "")
+          if [ -z "$PR_NUMBER" ]; then echo "RELEASE_NOTES=" >> $GITHUB_ENV; exit 0; fi
+          cleaned_notes=$(gh pr view "$PR_NUMBER" --json body -q '.body' | awk 'BEGIN{found=0} /^- Update/{found=1} /^<!-- Reviewable:start -->/{found=0;next} found' | sed '/^- - -$/d' | sed '/^[[:space:]]*$/d')
+          echo "RELEASE_NOTES<<EOF" >> $GITHUB_ENV
+          echo "$cleaned_notes" >> $GITHUB_ENV
+          echo "EOF" >> $GITHUB_ENV
+
+      - name: Update CHANGELOG.md
+        run: |
+          awk -v ver="${{ inputs.unity_version }}" -v notes="$RELEASE_NOTES" \
+            '/^## \[Unreleased\]/ { print $0; print "## [" ver "]\n### Changed"; print notes "\n"; next } { print $0 }' \
+            OneSignalExample/Assets/OneSignal/CHANGELOG.md > /tmp/changelog.tmp && mv /tmp/changelog.tmp OneSignalExample/Assets/OneSignal/CHANGELOG.md
+          git add . && git commit -m "Update CHANGELOG.md for ${{ inputs.unity_version }}" && git push