Update react monorepo to v16.12.0 (#1032)
Update react monorepo to v16.12.0 (#1032)

Co-authored-by: WhiteSource Renovate <4e3adfceaad659ebdd3c586014a0b3732b1fa93f@gmail.com>

reactjs/React.NET,reactjs/React.NET,reactjs/React.NET,reactjs/React.NET,reactjs/React.NET,reactjs/React.NET