[BEAM-4229] Downgrade BigQuery to fix Spanner

[apilloud]

Both Spanner and BigQuery depend on google-cloud-core. The spanner library requires 1.2.0, the BigQuery library requires 1.27.0, and we include 1.0.2 in our build_rules.gradle. Downgrading the BigQuery library fixes the issue. We can't upgrade spanner because of a conflict with gRPC and Protobuf. This shouldn't be a problem as we are only using this BigQuery library for schema conversion, our actual IO uses an even older library.

---

Follow this checklist to help us incorporate your contribution quickly and easily:

• Make sure there is a JIRA issue filed for the change (usually before you start working on it). Trivial changes like typos do not require a JIRA issue. Your pull request should address just this issue, without pulling in other changes.
• Format the pull request title like [BEAM-XXX] Fixes bug in ApproximateQuantiles, where you replace BEAM-XXX with the appropriate JIRA issue.
• Write a pull request description that is detailed enough to understand:
  • What the pull request does
  • Why it does it
  • How it does it
  • Why this approach
• Each commit in the pull request should have a meaningful subject line and body.
• Run ./gradlew build to make sure basic checks pass. A more thorough check will be performed on your pull request automatically.
• If this contribution is large, please file an Apache Individual Contributor License Agreement.

[apilloud]

This is an impossible change due to various version incompatibility.