[Singleton Service][Get pattern by language&region] plurals rule should always follow with language

[nannany00]

Singleton Service API:
GET /i18n/api/v2/formatting/pattern (Get pattern from CLDR)

This API is used to provide the pattern data for dates/numbers/currencies/plurals/measurements from CLDR according to the requested language and region.

Plurals rule is related to the translation content, it should always follow with language, as Singleton provides translation by language.

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This issue is:
When the combined locale of language and region is valid, the plurals rule is following the combined locale, not language.

Example:
language=pt; region=PT; scope=plurals

Actual Result is:
it will return the plurals rule of pt-PT.

Expected Result is:
it should return the plurals rule of pt.

[nannany00]

Based on current code, still has issue here:
When language=pt-PT, region=PT, the plurals rule should be pt-PT, not pt.

Please help to check.

[lyiyu66]

Plurals rule issue has been fixed on current code.