Add Private space Delete settings page inside PS settings page

Contains implementation of settings page for Delete private space
controller inside private space settings page.
- On selecting to delete private space displays list of account signed in
to private profile and deletes the private space after authentication.
- Shows a toast message after private space is deleted

- Adds dependency for setupdesgin loading layout to show a loading
  screen while deletion of private space is in progress.

Recording Link : b/318383729
go/ss/4Aq3rmbSGHMHesK.png

Bug: 318383729
Test: atest DeletePrivateSpaceControllerTest

Change-Id: Ia1730915e2469b47823c507f9ef6cd8f63c99baf

src/com/android/settings/privatespace/PrivateSpaceMaintainer.java

@@ -75,7 +75,8 @@ public class PrivateSpaceMaintainer {
      *
      * <p> This method should be used by the Private Space Setup Flow ONLY.
      */
-    final synchronized boolean createPrivateSpace() {
+    @VisibleForTesting
+    public final synchronized boolean createPrivateSpace() {
         if (!Flags.allowPrivateProfile()) {
             return false;
         }