MT#57598 Add explicit_defaults_for_timestamp option

It was added to my.cnf in templates.git:3e304fb6 so add it to mariadb
startup options.

Change-Id: I9ee8b46a75390d286e6d756eb1c1f92785d8c4ab
(cherry picked from commit cf6f52f592)

build_utils/ngcp-build-schema-files

@@ -46,6 +46,7 @@ mysqld_options+=("--sql-mode=NO_ENGINE_SUBSTITUTION")
 mysqld_options+=("--character-set-server=utf8")
 mysqld_options+=("--init-connect='SET NAMES utf8; SET collation_connection = utf8_general_ci; SET sql_mode = STRICT_TRANS_TABLES'")
 mysqld_options+=("--collation-server=utf8_general_ci")
+mysqld_options+=("--explicit-defaults-for-timestamp=0")
 
 mariadbd "${mysqld_options[@]}" &>/dev/null &