Fix NPE in dialpad page.

Instead of checking getActivity(), check getView() to make sure the view has been created.

Fixes: 146831169
Change-Id: Ied8e7aed5e0a21e084818d4ce64003ce15fa38ba
Test: mma
diff --git a/src/com/android/car/dialer/ui/dialpad/DialpadFragment.java b/src/com/android/car/dialer/ui/dialpad/DialpadFragment.java
index 0b2063a..4438980 100644
--- a/src/com/android/car/dialer/ui/dialpad/DialpadFragment.java
+++ b/src/com/android/car/dialer/ui/dialpad/DialpadFragment.java
@@ -216,7 +216,7 @@
 
     @Override
     void presentDialedNumber(@NonNull StringBuffer number) {
-        if (getActivity() == null) {
+        if (getView() == null) {
             return;
         }