Log exception if we hit an error parsing an incoming SMS message.

This will help debug b/2197566.  We should have been logging the error
anyway.

telephony/java/com/android/internal/telephony/SMSDispatcher.java

@@ -303,6 +303,7 @@ public abstract class SMSDispatcher extends Handler {
                     notifyAndAcknowledgeLastIncomingSms(handled, result, null);
                 }
             } catch (RuntimeException ex) {
+                Log.e(TAG, "Exception dispatching message", ex);
                 notifyAndAcknowledgeLastIncomingSms(false, Intents.RESULT_SMS_GENERIC_ERROR, null);
             }
 

telephony/java/com/android/internal/telephony/cdma/CdmaSMSDispatcher.java

@@ -100,6 +100,7 @@ final class CdmaSMSDispatcher extends SMSDispatcher {
 
         // If sms is null, means there was a parsing error.
         if (smsb == null) {
+            Log.e(TAG, "dispatchMessage: message is null");
             return Intents.RESULT_SMS_GENERIC_ERROR;
         }