Bug#22067 rpl_rbr_to_sbr and some other fail if NDB is default storage

A query SET @@GLOBAL.binlog_format = ... returns an error when NDB is the
default storage. This fails some tests invoking the set binlog_format explicitly.
because the var turns to be read-only.
  
  In the following are files and method to fix if needed.
  
  t/
  ndb_binlog_basic2.test         # here the failure is benign
  rpl_rbr_to_sbr.test            # does not check any ndb features =>           
 
  .                              # => not_ndb_default is enough
  rpl_row_basic_8partition.test  # set binlog_format can be replaced
  rpl_switch_stm_row_mixed.test  # does not check any ndb features =>
  .                              # => not_ndb_default is enough
  
  two more invoking invoke extra/rpl_truncate_helper.test
  
  rpl_truncate_2myisam           # to be fixed with not_ndb_default
  rpl_truncate_3innodb           # same as above
  .                              # because there is a dedicated to ndb .        
 
  .                              # rpl_truncate_7ndb* suit.

Adapting/testing a new implement
--source include/safe_set_to_maybe_ro_var.inc
to avoid abort due to the error using binlog_format as application.

mysql-test/include/safe_set_to_maybe_ro_var.inc

@@ -0,0 +1,23 @@
+# to mask out the error - never abort neither log in result file - in setting 
+# to read-only variable.
+# It is assumed that the new value is equal to one the var was set to.
+# Such situation happens particularily with binlog_format that becomes read-only
+# with ndb default storage.
+#
+# when generate results always watch the file to find what is expected,
+# the SET query may fail
+
+# script accepts $maybe_ro_var the var name and $val4var the value
+
+### USAGE:
+### let $maybe_ro_var= ...
+### let $val4var= ...
+### include/safe_set_to_maybe_ro_var.inc
+
+--disable_result_log
+--disable_abort_on_error
+eval SET $maybe_ro_var = $val4var;
+--enable_abort_on_error
+--enable_result_log
+
+eval SELECT $maybe_ro_var;