Yes, ECC memory is supported. You should only use the memory modules that Hitachi Vantara provides with the HCP system and HCP system upgrades.
As of v8.1.2 in April 2019 the shipping memory module with the HCP G10 is Quanta ATR5XAGR505. This corresponds to Samsung M393A4K40CB1-CRC4Q. This is an ECC memory module. Do not supply your own memory - it must be purchased through Hitachi Vantara