Fix the ripple effect on Fire TV diamond and the colors on the views it affects

[mcomella]

By all buttons, I mean the overlay and settings on the homescreen. Two problems:

• The ripple does not appear on the 4k Fire TV diamond (though there is a fade out)
• The ripple adds an opacity layer over the buttons and changes the colors we carefully selected for the overlay: https://user-images.githubusercontent.com/287322/37064538-32c7176e-2152-11e8-8957-fd11f483f067.png (it looks like the ripple can use selectors for its colors: could we just use the colors we want as the selector states and it'll ripple with those instead?)

[mcomella]

I noticed removed the <item id="mask"> thing and it's children will let the ripple work on the diamond (but then it's unconstrained).

[mcomella]

I also tried the simple formats from https://developer.android.com/reference/android/graphics/drawable/RippleDrawable.html like:

<!-- A green ripple drawn atop a black rectangle. --/>
 <ripple android:color="#ff00ff00">
   <item android:drawable="@android:color/black" />
 </ripple>

And it works on the emulator but not on device.

Two thoughts:

• We should try changing parameters of the RippleDrawable, like the radius, the hotspot, etc. to see if that affects the ripple
• Maybe we should copy the AOSP version of RippleDrawable and import it to see if that fixes the issue.

[mcomella]

Can we reproduce this with API 25 (or whatever the diamond is) emulators? I'm running an API 22 emulator, like the Stick.

[mcomella]

We should also make sure the behavior we're seeing is consistent in a new app (i.e. ripple works on stick but not on diamond so our styles aren't screwing this up).

[mcomella]

I'm also opting to remove the ripple in settings: see #641 and the opened PR.