Do not count print jobs if printing is not available.

Bug: 27339883
Change-Id: I0b0761917798581e831e8b2692fdc9c5fefb1155
diff --git a/src/com/android/settings/print/PrintSettingsFragment.java b/src/com/android/settings/print/PrintSettingsFragment.java
index b59c297..8240fc1 100644
--- a/src/com/android/settings/print/PrintSettingsFragment.java
+++ b/src/com/android/settings/print/PrintSettingsFragment.java
@@ -605,11 +605,13 @@
 
         @Override
         public void setListening(boolean isListening) {
-            if (isListening) {
-                mPrintManager.addPrintJobStateChangeListener(this);
-                onPrintJobStateChanged(null);
-            } else {
-                mPrintManager.removePrintJobStateChangeListener(this);
+            if (mPrintManager != null) {
+                if (isListening) {
+                    mPrintManager.addPrintJobStateChangeListener(this);
+                    onPrintJobStateChanged(null);
+                } else {
+                    mPrintManager.removePrintJobStateChangeListener(this);
+                }
             }
         }