Today we softly warn about running with the client VM. However, we
should really refuse to start in production mode if running with the
client VM as the performance of the client VM is too devastating for a
server application. This commit adds an option to jvm.options to ensure
that we are starting with the server VM (on all 32-bit non-Windows
platforms on server-class machines (2+ CPUs, 2+ GB physical RAM) this is
the default and on all 64-bit platforms this is the only option) and
adds a bootstrap check for the client VM.

Relates elastic#18155