Writable was added to HostPathMount in v1alpha1 in order to control if an extra
volume is mounted in read only or writable mode.
Usually, in Kubernetes, this option is referred to as ReadOnly, instead of
Writable and is defaulted to `false`. However, at the time, all extra volumes
to pods were defaulted to read-only. Therefore, to avoid changes to existing
v1alpha1 configs, this option had to be added with reversed meaning.
Hence, it's called `writable`.
Now, with the migration towards v1beta1, we can safely change this to ReadOnly
and get it in sync with the reset of Kubernetes.
Signed-off-by: Rostislav M. Georgiev <rostislavg@vmware.com>
6c9e347e31