BUG#26042764: BACKPORT BUG#25642343 AND BUG#24311527 TO 5.7

BUG#24311527: PLUGIN-LOAD FAILS AFTER MYSQLD --INITIALIZE BUG#25642343: THE SERVER SHOULD HAVE A DEFAULT USER FOR THE SERVER SESION SERVICE Update initialize-sha256 test.

Author: nacarvalho

mysql-test/r/initialize-sha256.result

@@ -21,6 +21,7 @@ SET PASSWORD='';
 SELECT user, host, plugin, LENGTH(authentication_string) > 0
 FROM mysql.user ORDER BY user;
 user	host	plugin	LENGTH(authentication_string) > 0
+mysql.session	localhost	mysql_native_password	1
 mysql.sys	localhost	mysql_native_password	1
 root	localhost	sha256_password	0
 CREATE DATABASE test;