docs: Removed self-referencing links on Apps and Games pages.

The "Distribute > Stories > Apps" and "Distribute > Stories > Games"
pages on DAC included cards that linked to the current page (in
other words, they were circular/self-referencing links).

Removed the metadata from the apps.html and games.html pages
accordingly.

Bug: 29881467
Change-Id: I2b6555ee565500e978ba3c4edef4d93b0bf9a239