デバイスのモデル（読み取り専用）
Exact format of model name is operating system dependent, for example iOS device names typically look
like "iPhone6,1", whereas Android device names are often in "manufacturer model" format
(e.g. "LGE Nexus 5" or "SAMSUNG-SM-G900A"). The returned model can also be a very generic name
(e.g. "PC") if the actual model name is not available or relevant on the current platform.
The returned value will usually be similar to the one shown in the operating system's "About Device" or "System Information" screen (or equivalent). This information will often also include the manufacturer.
Will return SystemInfo.unsupportedIdentifier on platforms which don't support this property.
See Also: deviceType.