Firebase Admin Java SDK v8.0.0

Bug Fixes

• fix: Using Java 8 in release and nightly builds (#573)

Miscellaneous

• [chore] Release 8.0.0 (#579)
• chore(deps): bump libraries-bom from 20.6.0 to 20.7.0 (#578)
• chore(deps): bump google-api-client-bom from 1.31.5 to 1.32.1 (#577)
• Drop 500 from the retriable errorcode list (#576)
• chore(deps): bump maven-javadoc-plugin from 3.2.0 to 3.3.0 (#572)
• chore(deps): bump maven-source-plugin from 2.2.1 to 3.2.1 (#563)
• chore(deps): bump slf4j-api from 1.7.30 to 1.7.31 (#574)
• chore(deps): bump libraries-bom from 20.4.0 to 20.6.0 (#571)
• Revert "chore(deps): bump maven-javadoc-plugin from 3.2.0 to 3.3.0" (#569)
• Adding detail RE default value of collapse key. (#568)
• chore(deps): bump maven-javadoc-plugin from 3.2.0 to 3.3.0 (#562)
• chore(deps): bump libraries-bom from 8.0.0 to 20.4.0 (#558)
• chore(deps): bump netty.version from 4.1.64.Final to 4.1.65.Final (#564)
• chore(deps): bump maven-antrun-plugin from 1.7 to 3.0.0 (#559)
• chore(deps): bump maven-javadoc-plugin from 2.10.4 to 3.2.0 (#539)
• chore(deps): bump netty.version from 4.1.63.Final to 4.1.64.Final (#560)
• chore(deps): bump maven-project-info-reports-plugin from 2.9 to 3.1.2 (#553)
• chore(deps): bump google-api-client-bom from 1.31.4 to 1.31.5 (#556)