Fix locale for UI tests

[fr0l]

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• [x ] I have read the README and CONTRIBUTING documents
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Contributor checklist

• [ x] My commits are rebased on the latest main branch
• [ x] My commits are in nice logical chunks
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• iDevice A, iOS X.Y.Z
• iDevice B, iOS Z.Y

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Description

This PR adds two arguments passed on Application Under Test launch: -AppleLocale en_US and -AppleLanguages (en)

This sets application locale to en_US in order to successfully run SignalUITests and SignalServiceKitTests on a Mac with locale set other than en_US (for example: en_GB).

Otherwise when running on non-en_US locale some tests fail with following error:

XCTAssertEqual failed: ("["+445215550100", "+5215550100", "+15215550100"]") is not equal to ("["+15215550100", "+5215550100"]") - searchText: 5215550100

Tests fail due to wrong phone prefix +44 instead of +1

With setting locale to en_US and language to en tests succeed.