Germans are bringing gold back into their own country, as opposed to holding it in other exchanges. They have neither increased nor decreased their supply.
China and India are world-class consumers of gold for jewelry, as expected of the world's most populous countries with a rising middle class. Gold is also used in microelectronic components. Chinese Banks on the other hand, have not increased their holdings according to your link. IE: China is not investing into Gold. They're using it.
As for Russian and Iraqi Central Banks buying up Gold between 2012 and today... well... they've already lost 10% on their investment as Gold has dropped in value between last year and today. I mean, if you wanna follow the example of Russian and Iraqi banks, you're welcome to do so. But I don't think anyone considers them a paragon of the investing world.