Add Privacy Notice + ToS to bottom of Help dialog

[cvan]

1. load https://hubs.mozilla.com/
2. notice the Mozilla, Mozilla Mixed Reality, and View Source links in the header
   
3. scroll down to the footer to notice the following: Terms of Use, Privacy Notice, and the made with 🦆by Mozilla
   

---

1. load https://hubs.mozilla.com/0h6bsjd7ofz/snoopy-soft-festivity
2. notice there is no Mozilla branding (nor Terms of Use, Privacy Notice, and View Source links; I could be missing them somewhere though)
   
   
   
3. is that intentional? (if so, apologies for filing this issue!)

notice the interstitial avatar-selection screen does though show the Terms of Use and Privacy Notice:

[gfodor]

Right now the design puts the brand on the loading screen -- the forcing function (as usual) is mobile. Earlier designs had the logo/brand on mobile entry flow screens but ultimately that screen space was freed up towards things of higher utility like the share and help icons. We do have more flexibility on desktop, but of course an excessive difference in terms of content/elements between desktop and mobile is often bad design.

WRT privacy policy/terms, that is also by design & guidance with legal (in terms of copy and placement on the 'account setup' dialog) but I agree it may make sense to find a way to surface those links in-game. Same issues as above, right now we probably will lose something in exchange for it because we're already pretty tight on real estate on small mobile screens (Samsung S5/iPhone 5) without overhauling the interaction model.

[gfodor]

We could probably stick the ToU and PN at the bottom of the help dialog now that it is scrollable.

[gfodor]

I've updated the title to reflect the actionable item for this