Fix issue #17329290: NPE during ContentProviderRecord.dump()

Don't NPE.

Change-Id: I5e59583e97b969b1739fc39a1520bd1930302313
diff --git a/services/core/java/com/android/server/am/ContentProviderRecord.java b/services/core/java/com/android/server/am/ContentProviderRecord.java
index ff22764..a37249d 100644
--- a/services/core/java/com/android/server/am/ContentProviderRecord.java
+++ b/services/core/java/com/android/server/am/ContentProviderRecord.java
@@ -166,8 +166,16 @@
         }
         if (full) {
             if (hasExternalProcessHandles()) {
-                pw.print(prefix); pw.print("externals=");
-                        pw.println(externalProcessTokenToHandle.size());
+                pw.print(prefix); pw.print("externals:");
+                if (externalProcessTokenToHandle != null) {
+                    pw.print(" w/token=");
+                    pw.print(externalProcessTokenToHandle.size());
+                }
+                if (externalProcessNoHandleCount > 0) {
+                    pw.print(" notoken=");
+                    pw.print(externalProcessNoHandleCount);
+                }
+                pw.println();
             }
         } else {
             if (connections.size() > 0 || externalProcessNoHandleCount > 0) {