Revert "Rename to test_mysql_strict_mode_disabled_dont_override_global_sql_mode"

This reverts commit babc24c1b07c1fd58b9b3249b0256f9b0d45c0f0.

Conflicts:

	activerecord/test/cases/adapters/mysql/connection_test.rb
	activerecord/test/cases/adapters/mysql2/connection_test.rb
Fix a bug where malformed query strings lead to 500

If a request contains an malformed query string, Rails responds with an
internal server error insted of a bad request. This is because
ActionDispatch::PublicExceptions calls request#formats and it raises an
ActionController::BadRequest from inside ActionDispatch::ShowExceptions,
hence the 500 error.

This commit changes PublicExceptions to catch BadRequest if raised from
request#formats.

fixes #11502
Merge pull request #16886 from yuki24/bugfix-bad-request-from-public-exception-4-1-stable

[4-1-stable] Fix a bug where malformed query strings lead to 500
Merge pull request #16486 from yahonda/backport_16196_to_4-1-stable

Revert "Rename to test_mysql_strict_mode_disabled_dont_override_global_sql_mode"
Put the CHANGELOG entry in the right place [ci skip]
Merge pull request #16914 from untidy-hair/fix_plugin_dummy_path_error

Use dynamic path for dummy app location in plugin's test_helper.rb
Conflicts:
	railties/CHANGELOG.md