With the addition of the KeystoneFernetKeys parameter, it's now possible
to do fernet key rotations using mistral, by modifying the
KeystoneFernetKeys variable in mistral; subsequently a rotation could
happen when doing a stack update.
So this re-enables the managing of the key files by puppet. However,
this is left configurable, as folks might want to manage those files
out-of-band.
bp keystone-fernet-rotation
Change-Id: Ic82fb8b8a76481a6e588047acf33a036cf444d7d