Finalize assets for screen casting.

Extend wifi display connection timeout.

Show a notification while connecting to wifi display.

Ensure that remote display providers are really trusted before
connecting to them.

Bug: 11257292
Change-Id: Iad0caaa30d7946df818bc75ade071f2e377f8a53

Conflicts:

	core/res/res/values/strings.xml
	services/java/com/android/server/display/WifiDisplayController.java