QuickSettings : Register/unregister cast tile one time

Don't do these operations every time the parent is visible/invisible,
it causes jank.

Repro:

Turn on wifi on a network w/ chromecast
Swipe down quick settings panel really fast

Change-Id: I3dfcd3610abe96e1bfdab06ef3b876ccf5140ceb
IconPackHelper: Don't respect an icons original size if too large.

  - Otherwise, if an application isn't following app icon guidelines,
  it can create an OOM situation when creating the new icon based
  on the original resource's height and width.

Change-Id: I9430445da5e393cdbf76ed9ebd9698bf30df6a95