See https://github.com/bundler/bundler/issues/6870
Bundler 2.x dropped support for Ruby < 2.3 so now we detect ruby
version and install last known to work version. This means that
newer OS will get newer versions of bundler.
Closes-Bug: #1810401
(cherry picked from commit 7acca40563)
Change-Id: Ibd1ff419d13cace906d4cd9765dc7b5486bc19a7