Merge pull request #10328 from pivanov/bug-880240

Bug 880240 - Update Firefox Logo on device r=@samjoch(cherry picked from commit 6a17febce2551cd3a764bb3bce39fe9ca88c5ca4)

Conflicts:
	shared/resources/branding/official/Browser@2x.png
	shared/resources/branding/official/about_logo@2x.png
	shared/resources/branding/official/initlogo@2x.png
	shared/resources/branding/official/logosmall@2x.png
	shared/resources/branding/official/powered@2x.png
	shared/resources/branding/official/privacy_sprite@2x.png