Change PreferenceController#getSummary return type.

Return CharSequence instead of String.

All user visible string should be modeled as CharSequence.

Bug: 73950519
Test: robotest
Change-Id: I30befef0c33f94351d4a2774e283bd1ed804aa8b

src/com/android/settings/applications/appinfo/DrawOverlayDetailPreferenceController.java

@@ -61,7 +61,7 @@ public class DrawOverlayDetailPreferenceController extends AppInfoPreferenceCont
     }
 
     @Override
-    public String getSummary() {
-        return DrawOverlayDetails.getSummary(mContext, mParent.getAppEntry()).toString();
+    public CharSequence getSummary() {
+        return DrawOverlayDetails.getSummary(mContext, mParent.getAppEntry());
     }
 }