Fix Log statement logic to ONLY fire if BluetoothMapClient is null.

Previously was firing if BMC was null OR if shouldLoadExistingMessages
was false, causing some misreports.

Bug: 138677994
Test: manual
Change-Id: I10f03fff12adfb12f352ed7db1805ee59de8013e
diff --git a/src/com/android/car/messenger/MessengerDelegate.java b/src/com/android/car/messenger/MessengerDelegate.java
index 643a58d..8c7b382 100644
--- a/src/com/android/car/messenger/MessengerDelegate.java
+++ b/src/com/android/car/messenger/MessengerDelegate.java
@@ -117,8 +117,10 @@
         L.d(TAG, "Device connected: \t%s", device.getAddress());
         mBTDeviceAddressToConnectionTimestamp.put(device.getAddress(), System.currentTimeMillis());
         synchronized (mMapClientLock) {
-            if (mBluetoothMapClient != null && mShouldLoadExistingMessages) {
-                mBluetoothMapClient.getUnreadMessages(device);
+            if (mBluetoothMapClient != null) {
+                if (mShouldLoadExistingMessages) {
+                    mBluetoothMapClient.getUnreadMessages(device);
+                }
             } else {
                 // onDeviceConnected should be sent by BluetoothMapClient, so log if we run into
                 // this strange case.