Fix tvOS iTests - Use UNITY_TVOS and disable Storage filesystem tests

[DellaBitta]

Description

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Fixes to the Storage, Database, Crashlytics and Messaging tests. These testapps has variable behavior based on the target device, and use UNITY_IOS or UNITY_ANDROID preprocessors to toggle off certain tests. These preprocessor definitions are automatically defined for us by Unity when building for the applicable platforms.

This change adds UNITY_TVOS where appropriate and makes it use the same tests & code as UNITY_IOS.

Additionally the Storage tests that download to disk have been disabled since tvOS does not have a dependable file system to test against.

Flaky tests that failed in CI were Installations, Messaging, and Functions. When verifying these tests locally on tvOS simulators, both Installations and Functions pass. Messaging has the same error result as our tests iOS on simulators, which I also verifed locally.

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Testing

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Integration Test CI

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Type of Change

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• Bug fix. Add the issue # below if applicable.
• New feature. A non-breaking change which adds functionality.
• Other, such as a build process or documentation change.

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