Remove FloatingTaskController & replace usages with Bubbles

Switch to using newly exposed method Bubbles#showAppBubble as what
FloatingTaskController does is no longer POR.

Calling this allows 1 bubble from a specific app to be added to the
stack. The only user of this method is NoteTaskController which is guarded by the NOTE_TASK.

Bug: 237678727
Test: treehugger
Change-Id: I47c5c010a050796eff848ba3fcabc40cf5fbd902

packages/SystemUI/src/com/android/systemui/SystemUIInitializer.java

@@ -97,7 +97,6 @@ public abstract class SystemUIInitializer {
                     .setDisplayAreaHelper(mWMComponent.getDisplayAreaHelper())
                     .setRecentTasks(mWMComponent.getRecentTasks())
                     .setBackAnimation(mWMComponent.getBackAnimation())
-                    .setFloatingTasks(mWMComponent.getFloatingTasks())
                     .setDesktopMode(mWMComponent.getDesktopMode());
 
             // Only initialize when not starting from tests since this currently initializes some
@@ -118,7 +117,6 @@ public abstract class SystemUIInitializer {
                     .setStartingSurface(Optional.ofNullable(null))
                     .setRecentTasks(Optional.ofNullable(null))
                     .setBackAnimation(Optional.ofNullable(null))
-                    .setFloatingTasks(Optional.ofNullable(null))
                     .setDesktopMode(Optional.ofNullable(null));
         }
         mSysUIComponent = builder.build();