Add illustration to final screen in PS setup and update existing illustrations.

Screenshots:
- go/ss/9KhqUSezFKHnyys.png

Recording link:
- b/321694009#comment2

Bug: 323156268
Bug: 321694009
Test: Verified manually
Change-Id: Ib8abc080f31cad0a9be3b73a1694be744c108a06

res/layout/private_space_advancing_screen.xml

@@ -26,12 +26,12 @@
                   android:layout_height="match_parent"
                   android:orientation="vertical">
         <ImageView
-            android:id="@+id/placeholder_image"
+            android:id="@+id/setup_advance_image"
             android:layout_width="match_parent"
             android:layout_height="0dp"
             android:layout_weight="1"
             android:contentDescription="@null"
-            android:src="@drawable/privatespace_setup_flow_placeholder"/>
+            android:src="@null"/>
 
         <TextView
             android:id="@+id/createMessage"

res/layout/private_space_education_screen.xml

@@ -34,13 +34,13 @@
         android:layout_height="wrap_content"
         android:orientation="vertical">
         <ImageView
-            android:id="@+id/placeholder_image"
+            android:id="@+id/setup_education_image"
             style="@style/SudContentIllustration"
             android:layout_width="match_parent"
             android:layout_marginLeft="24dp"
             android:layout_marginRight="24dp"
             android:layout_height="wrap_content"
-            android:src="@drawable/privatespace_placeholder_image"/>
+            android:src="@drawable/private_space_illustration"/>
         <TextView
             style="@style/PrivateSpaceSetupSubHeaderStyle"
             android:text="@string/private_space_how_title"/>

res/layout/private_space_setlock_screen.xml

@@ -37,7 +37,7 @@
             android:layout_height="match_parent"
             android:scaleType="fitCenter"
             android:contentDescription="@null"
-            android:src="@drawable/privatespace_lock_placeholder"/>
+            android:src="@drawable/private_space_choose_lock_illustration"/>
 
     </com.google.android.setupdesign.view.FillContentLayout>
 </com.google.android.setupdesign.GlifLayout>

res/layout/private_space_setup_success.xml

@@ -24,4 +24,13 @@
     app:sucHeaderText="@string/private_space_success_title"
     app:sudDescriptionText="@string/private_space_access_text"
     android:icon="@drawable/ic_privatespace_done">
+
+    <ImageView
+        android:id="@+id/privatespace_success_image"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        android:layout_marginLeft="24dp"
+        android:layout_marginRight="24dp"
+        android:src="@drawable/private_space_illustration"/>
+
 </com.google.android.setupdesign.GlifLayout>