Add a test for alleged double escaping of formatWithParams.
Add a test for alleged double escaping of formatWithParams.

RELNOTES: None.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=209010480

lucidsoftware/closure-library,lucidsoftware/closure-library,teppeis/closure-library,teppeis/closure-library,teppeis/closure-library,google/closure-library,google/closure-library,google/closure-library,teppeis/closure-library,lucidsoftware/closure-library,google/closure-library,lucidsoftware/closure-library,google/closure-library