Add missing strings

[guillogo]

Hi Dan,

Some missing strings are causing unit tests fail:

There was 1 failure:

1) core_privacy\privacy\provider_test::test_metadata_provider with data set "local_recompletion" ('local_recompletion', 'local_recompletion\privacy\provider')
Expectation failed, debugging() was triggered.
Debugging: Invalid get_string() identifier: 'privacy:metadata:local_recompletion_cha' or component 'local_recompletion'. Perhaps you are missing $string['privacy:metadata:local_recompletion_cha'] = ''; in /siteroot/local/recompletion/lang/en/local_recompletion.php?
* line 356 of /lib/classes/string_manager_standard.php: call to debugging()
* line 7419 of /lib/moodlelib.php: call to core_string_manager_standard->get_string()
* line 152 of /privacy/tests/privacy/provider_test.php: call to get_string()
* line 1548 of /vendor/phpunit/phpunit/src/Framework/TestCase.php: call to core_privacy\privacy\provider_test->test_metadata_provider()
* line 1154 of /vendor/phpunit/phpunit/src/Framework/TestCase.php: call to PHPUnit\Framework\TestCase->runTest()
* line 80 of /lib/phpunit/classes/advanced_testcase.php: call to PHPUnit\Framework\TestCase->runBare()
* line 728 of /vendor/phpunit/phpunit/src/Framework/TestResult.php: call to advanced_testcase->runBare()
* line 904 of /vendor/phpunit/phpunit/src/Framework/TestCase.php: call to PHPUnit\Framework\TestResult->run()
* line 675 of /vendor/phpunit/phpunit/src/Framework/TestSuite.php: call to PHPUnit\Framework\TestCase->run()
* line 675 of /vendor/phpunit/phpunit/src/Framework/TestSuite.php: call to PHPUnit\Framework\TestSuite->run()
* line 661 of /vendor/phpunit/phpunit/src/TextUI/TestRunner.php: call to PHPUnit\Framework\TestSuite->run()
* line 144 of /vendor/phpunit/phpunit/src/TextUI/Command.php: call to PHPUnit\TextUI\TestRunner->run()
* line 97 of /vendor/phpunit/phpunit/src/TextUI/Command.php: call to PHPUnit\TextUI\Command->run()
* line 97 of phpvfscomposer:///vendor/phpunit/phpunit/phpunit: call to PHPUnit\TextUI\Command::main()
* line 118 of /vendor/bin/phpunit: call to include()

Failed asserting that 1 matches expected 0.

/siteroot/lib/phpunit/classes/advanced_testcase.php:398
/siteroot/privacy/tests/privacy/provider_test.php:153
/siteroot/lib/phpunit/classes/advanced_testcase.php:80
phpvfscomposer:///siteroot/vendor/phpunit/phpunit/phpunit:97

FAILURES!
Tests: 1497, Assertions: 11670, Failures: 1.

[danmarsden]

thanks for the report and the PR - merged that in!