Cleanup API checks for P, Q, and R.

Test: Build with gradle
Flag: NA
Change-Id: I3ef17090741d14bebd76cf09cf3dc5ac4f11e686

src/com/android/launcher3/provider/RestoreDbTask.java

@@ -326,9 +326,6 @@ public class RestoreDbTask {
      */
     private UserHandle getUserForAncestralSerialNumber(BackupManager backupManager,
             long ancestralSerialNumber) {
-        if (!Utilities.ATLEAST_Q) {
-            return null;
-        }
         return backupManager.getUserForAncestralSerialNumber(ancestralSerialNumber);
     }