`LocalizationManagerTests.GetDynamicStringOrEnglish` fails without side effects of test

[ermshiperete]

The comments for GetDynamicStringOrEnglish test method suggests that the string given as parameter should always win. This is tested with four assertions for different cases.

However, the first case where we ask for "en" modifies the xliff data structure. This causes the second test where we ask for "ar" to pass because when we ask for the fallback the modified string from the first test gets returned.

If the first assert gets commented out the test fails, suggesting that the implementation doesn't do what the method tries to test.