Alpha: Create CTA for watchlist only once

It seems in alpha due to the page-loaded event currently firing (see 45299)
this gets created twice resulting in two DOM elements

Should probably be done globally to avoid this in the meantime

Change-Id: I64a2ebff747af7c1ff0d63e9d4b584dabb06a19f
Merge "Alpha: Create CTA for watchlist only once"