Adds launcher-side support for the SmartSpace shared element transition.

This adds a new SmartSpaceTransitionController, which Launcher uses to register its SmartSpace with SysUI so that SysUI can manipulate it during an unlock animation.

Bug: 187025480
Test: manual with all the different lock types
Change-Id: I8ebf33e1a253e90f97875548113106cd828721e0

quickstep/src/com/android/launcher3/BaseQuickstepLauncher.java

@@ -184,7 +184,7 @@ public abstract class BaseQuickstepLauncher extends Launcher
     }
 
     @Override
-    protected void onUiChangedWhileSleeping() {
+    public void onUiChangedWhileSleeping() {
         // Remove the snapshot because the content view may have obvious changes.
         UI_HELPER_EXECUTOR.execute(
                 () -> ActivityManagerWrapper.getInstance().invalidateHomeTaskSnapshot(this));