QuickSettings: Invert long click and click actions

[log]

Change-Id: I1800ec53f67dc84966aef8f769423a1f553b0b1f
QS: Add loading when toggling state, and longpress brightness

Change-Id: Ifa133e15259b45da4c625ce47b3f12209bcd1b94

Conflicts:
	packages/SystemUI/src/com/android/systemui/statusbar/phone/QuickSettings.java
	packages/SystemUI/src/com/android/systemui/statusbar/phone/QuickSettingsTileView.java
QS: Add flippable tiles

This commit adds support for tiles that can be flipped to reveal
more information, as well as a two flippable tiles:
 - A Wi-Fi back tile displaying the current IP address in case
   you're connected to a Wi-Fi network. Tapping the back of the
   tile opens the tethering settings, if supported.
 - A Bluetooth back tile displaying the number of paired devices,
   and tapping it toggles discoverability.

This commit also moves the loading spinner to the BasicTile, as
it is only supported in basic_tile layout.

[log]

Change-Id: I73350c80f91894c16d3cd42dbce8b85e9a26bc31
Bring back the status bar activity indicators for mobile data and wifi

Google were nice enough to create xxhdpi drawables for us before removing them.

Reverts "Remove signal/wifi activity indicator icon overlays."

This reverts commit fcc901c10bffdfb9c6b31e676dec36b47d949979.

Change-Id: I7aa85f7c8442c45d17e42cac7823dfe93e3f24c1