RUM-1096 Fix os name in log events

[maciejburda]

What and why?

Fixes OS name for log events.

Before fix:

After fix:

How?

Change was quite simple. We should use osName instead of name from context.device.

Review checklist

• Feature or bugfix MUST have appropriate tests (unit, integration)
• Make sure each commit and the PR mention the Issue number or JIRA reference
• Add CHANGELOG entry for user facing changes

Custom CI job configuration (optional)

• Run unit tests for Core, RUM, Trace, Logs, CR and WVT
• Run unit tests for Session Replay
• Run integration tests
• Run smoke tests
• Run tests for tools/

[ganeshnj]

Looks like this change broke some test

testSendingLogWithDefaultLogger()

/Users/vagrant/git/DatadogCore/Tests/Datadog/LoggerTests.swift:58 - XCTAssertEqual failed: ("{
    "_dd" =     {
        device =         {
            architecture = testArch;
        };
    };
    "build_version" = 1;
    date = "2019-12-15T10:00:00.000Z";
    ddtags = "env:tests,version:1.0.0";
    "logger.name" = "com.datadoghq.ios-sdk";
    "logger.thread_name" = main;
    "logger.version" = "1.2.3";
    message = message;
    os =     {
        build = FFFFFF;
        name = abc;
        version = "1.0";
    };
    service = "default-service-name";
    status = debug;
    version = "1.0.0";
}") is not equal to ("{
    "_dd" =     {
        device =         {
            architecture = testArch;
        };
    };
    "build_version" = 1;
    date = "2019-12-15T10:00:00.000Z";
    ddtags = "env:tests,version:1.0.0";
    "logger.name" = "com.datadoghq.ios-sdk";
    "logger.thread_name" = main;
    "logger.version" = "1.2.3";
    message = message;
    os =     {
        build = FFFFFF;
        name = te...

[maciejburda]

Thanks! I'll double check this.

[maciejburda]

#1499