The _second-quarter_ GDP growth at the annualized rate is indeed at 4.2% (up from 2.2% for the first quarter of 2018), according to CNBC, based on stats from the US department of commerce.
CNBC indirectly attributes some of this to actions taken by Trump (though it doubts that these will be long-term beneficial for the GDP):
> But the robust growth in the second quarter is unlikely to be sustained given the one-off drivers such as a $1.5 trillion tax cut package, which provided a jolt to consumer spending after a lackluster first quarter, and a front-loading of soybean exports to China to beat retaliatory trade tariffs.
Quarterly (as opposed to annual) GDP of above 4% are not that uncommon; it for example happened 4 times under Obama. For an overview of the quarterly GDP 2011-2018, see here.
It should also be noted that the Obama quote seems to be entirely made up.