Fix NPE in CallAudioRouteController

This CL fixes a NullPointerException that can occur in CallAudioRouteController when the pending dest audio route is null.

Bug: 378005958
Change-Id: I16b7dd18e6076583aa2defdbdd3298862b85acce
Flag: EXEMPT bugfix
Test: Manual
diff --git a/src/com/android/server/telecom/CallAudioRouteController.java b/src/com/android/server/telecom/CallAudioRouteController.java
index d826b9d..bce2027 100644
--- a/src/com/android/server/telecom/CallAudioRouteController.java
+++ b/src/com/android/server/telecom/CallAudioRouteController.java
@@ -1015,6 +1015,7 @@
         Log.i(this, "handleSwitchBaselineRoute: includeBluetooth: %b, "
                 + "btAddressToExclude: %s", includeBluetooth, btAddressToExclude);
         boolean areExcludedBtAndDestBtSame = btAddressToExclude != null
+                && mPendingAudioRoute.getDestRoute() != null
                 && Objects.equals(btAddressToExclude, mPendingAudioRoute.getDestRoute()
                 .getBluetoothAddress());
         Pair<Integer, String> btDevicePendingMsg =