Revert to 2020.2 as latest on mac for the 2021-05-11 release
Revert to 2020.2 as latest on mac for the 2021-05-11 release

PiperOrigin-RevId: 374403644

bazelbuild/intellij,bazelbuild/intellij,bazelbuild/intellij,bazelbuild/intellij,bazelbuild/intellij,bazelbuild/intellij,bazelbuild/intellij