Problem:
=======
- InnoDB iterates the fil_system space list to encrypt the
tablespace in case of key rotation. But it is not
necessary for any encryption plugin which doesn't do
key version rotation.

Solution:
=========
- Introduce a new variable called srv_encrypt_rotate to
indicate whether encryption plugin does key rotation

fil_space_crypt_t::key_get_latest_version(): Enable the
srv_encrypt_rotate only once if current key version is
higher than innodb_encyrption_rotate_key_age

fil_crypt_must_default_encrypt(): Default encryption tables
should be added to default_encryp_tables list if
innodb_encyrption_rotate_key_age is zero and encryption
plugin doesn't do key version rotation

fil_space_create(): Add the newly created space to
default_encrypt_tables list if
fil_crypt_must_default_encrypt() returns true

Removed the nondeterministic select from
innodb-key-rotation-disable test. By default,
InnoDB adds the tablespace to the rotation list and
background crypt thread does encryption of tablespace.
So these select doesn't give reliable results.