feat: migrate to OTEL and enable metrics by default (#2166)

* feat: migrate to OTEL exporter (#1788) * feat: migrate exporter to OTEL * address comments * filter out only bigtable metrics * fix test * use the bom * update * update * update completeResultCode * add a comment * address comments * address comments * update pom * small fix * also check timestamp * address comment * updates * update * do not block on shutdown * chore: refactor factory class (#2081) * chore: refactor TracerFactory creation (#2102) * feat: migrate built in metrics to OTEL (#1796) * feat: migrate exporter to OTEL * address comments * filter out only bigtable metrics * fix test * use the bom * update * update * feat: migrate builtin metrics to OTEl * update completeResultCode * add a comment * udpate * fix tests * remove unrelated changes * fix tests * add documentation * fix test * merge exporter changes * address comments * rebase on otel * revert changes in stats * fix import * update * merge back the endpoint change * refactor constants and settings * refactor and fix tests * remove unused dependency * add some javadoc * address part of the comments * update test * test with nano * measure everything in nanos and publish with double histogram * address comments * fix test * add toString * merge from main * feat: migrate per connection error count metric to otel (#2133) * feat: migrate per connection error count metric to otel * update test * address comments * remove unnecessary check * clean up statsRecorder * remove dependency * address comments * feat: migrate per connection error exporter to otel (#2152) * chore: clean up stats package (#2163) * 🦉 Updates from OwlBot post-processor See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md * fix clirr and integration test * fix clirr and integration test * 🦉 Updates from OwlBot post-processor See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md * log more information on test failures * address comments * 🦉 Updates from OwlBot post-processor See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md * include version * fix flaky test * remove otel dependencies since they're added to shared dependencies * backport new tests since 2.37 * set feature flag when metrics is enabled * record metrics whenever it's registered * record metrics whenever it's registered * 🦉 Updates from OwlBot post-processor See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md * 🦉 Updates from OwlBot post-processor See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md * remove stale reference * clean up --------- Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

Author: mutianf