fix(javadocs): remove ampersand from pdl causing issue in doc generation for openapi

[RyanHolstien]

Checklist

• The PR conforms to DataHub's Contributing Guideline (particularly Commit Message Format)
• Links to related issues (if applicable)
• Tests for the changes have been added/updated (if applicable)
• Docs related to the changes have been added/updated (if applicable). If a new feature has been added a Usage Guide has been added for the same.
• For any breaking change/potential downtime/deprecation/big changes an entry has been made in Updating DataHub

[github-actions]

Unit Test Results (metadata ingestion)

       8 files         8 suites   57m 0s ⏱️
   661 tests    658 ✔️ 3 💤 0 ❌
1 322 runs  1 316 ✔️ 6 💤 0 ❌

Results for commit f8aff6e.

[github-actions]

Unit Test Results (build & test)

517 tests  ±0   517 ✔️ ±0   9m 32s ⏱️ +50s
121 suites ±0       0 💤 ±0 
121 files   ±0       0 ❌ ±0 

Results for commit f8aff6e. ± Comparison against base commit b0fc67b.