Enhance Github release notes (#1238)

*Issue #, if available:*

*Description of changes:*
DO NOT MERGE until
#1163
has been merged.

Add CHANGELOG entries to Github release notes and use headers to
separate new changes, upstream components, release artifacts, and Lambda
layer ARNs.

By submitting this pull request, I confirm that my contribution is made
under the terms of the Apache 2.0 license.

---------

Co-authored-by: Jonathan Lee <[email protected]>

Author: ezhang6811

.github/workflows/release-build.yml

@@ -74,8 +74,10 @@ jobs:
     steps:
       - name: Set up regions matrix
         id: set-matrix
+        env:
+          AWS_REGIONS: ${{ github.event.inputs.aws_region }}
         run: |
-          IFS=',' read -ra REGIONS <<< "${{ github.event.inputs.aws_region }}"
+          IFS=',' read -ra REGIONS <<< "$AWS_REGIONS"
           MATRIX="["
           for region in "${REGIONS[@]}"; do
             trimmed_region=$(echo "$region" | xargs)
@@ -180,8 +182,10 @@ jobs:
           load: true
 
       - name: Test docker image
+        env:
+          VERSION: ${{ github.event.inputs.version }}
         shell: bash
-        run: .github/scripts/test-adot-javaagent-image.sh "${{ env.TEST_TAG }}" "${{ github.event.inputs.version }}"
+        run: .github/scripts/test-adot-javaagent-image.sh "${{ env.TEST_TAG }}" "$VERSION"
 
       - name: Build and push image
         uses: docker/build-push-action@v5
@@ -380,34 +384,57 @@ jobs:
           name: layer.zip
 
       - name: Rename artifacts
+        env:
+          VERSION: ${{ github.event.inputs.version }}
         run: |
-          cp "aws-opentelemetry-agent-${{ github.event.inputs.version }}.jar" ${{ env.ARTIFACT_NAME }}
+          cp "aws-opentelemetry-agent-$VERSION.jar" ${{ env.ARTIFACT_NAME }}
           cp aws-opentelemetry-java-layer.zip layer.zip
 
       # Publish to GitHub releases
       - name: Create GH release
         id: create_release
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          VERSION: ${{ github.event.inputs.version }}
         run: |
           # Extract versions from dependency files
           OTEL_INSTRUMENTATION_VERSION=$(grep "val otelVersion" dependencyManagement/build.gradle.kts | sed 's/.*= "\([^"]*\)".*/\1/')
           OTEL_CONTRIB_VERSION=$(grep "io.opentelemetry.contrib:opentelemetry-aws-xray" dependencyManagement/build.gradle.kts | sed 's/.*:\([^"]*\)".*/\1/')
 
+          # Extract CHANGELOG entries for this version
+          CHANGELOG_ENTRIES=$(python3 -c "
+          import re, os
+          version = os.environ['VERSION']
+          with open('CHANGELOG.md', 'r') as f:
+              content = f.read()
+          version_pattern = rf'## v{re.escape(version)}.*?\n(.*?)(?=\n## |\Z)'
+          version_match = re.search(version_pattern, content, re.DOTALL)
+          if version_match:
+              entries = version_match.group(1).strip()
+              if entries:
+                  print(entries)
+          ")
+
           # Create release notes
           cat > release_notes.md << EOF
-          This release contains updates of the following upstream components:
+          $(if [ -n "$CHANGELOG_ENTRIES" ]; then echo "## What's Changed"; echo "$CHANGELOG_ENTRIES"; echo ""; fi)
 
-          OpenTelemetry Java Contrib - $OTEL_CONTRIB_VERSION
-          Opentelemetry Instrumentation for Java - $OTEL_INSTRUMENTATION_VERSION
+          ## Upstream Components
 
-          This release also publishes to public ECR and Maven Central.
-          * See ADOT Java auto-instrumentation Docker image v${{ github.event.inputs.version }} in our public ECR repository:
+          - \`OpenTelemetry Java Contrib\` - $OTEL_CONTRIB_VERSION
+          - \`Opentelemetry Instrumentation for Java\` - $OTEL_INSTRUMENTATION_VERSION
+
+          ## Release Artifacts
+
+          This release publishes to public ECR and Maven Central.
+          * See ADOT Java auto-instrumentation Docker image v$VERSION in our public ECR repository:
           https://gallery.ecr.aws/aws-observability/adot-autoinstrumentation-java
-          * See version ${{ github.event.inputs.version }} in our Maven Central repository:
+          * See version $VERSION in our Maven Central repository:
           https://central.sonatype.com/artifact/software.amazon.opentelemetry/aws-opentelemetry-agent
 
-          This release also includes the AWS OpenTelemetry Lambda Layer for Java version ${{ github.event.inputs.version }}-$(echo $GITHUB_SHA | cut -c1-7).
+          ## Lambda Layer
+
+          This release includes the AWS OpenTelemetry Lambda Layer for Java version $VERSION-$(echo $GITHUB_SHA | cut -c1-7).
 
           Lambda Layer ARNs:
           ${{ needs.generate-lambda-release-note.outputs.layer-note }}
@@ -417,10 +444,10 @@ jobs:
           shasum -a 256 layer.zip > layer.zip.sha256
 
           gh release create --target "$GITHUB_REF_NAME" \
-             --title "Release v${{ github.event.inputs.version }}" \
+             --title "Release v$VERSION" \
              --notes-file release_notes.md \
              --draft \
-             "v${{ github.event.inputs.version }}" \
+             "v$VERSION" \
              ${{ env.ARTIFACT_NAME }} \
              ${{ env.ARTIFACT_NAME }}.sha256 \
              layer.zip \