Do not wtf when the systemui is not present.

Not all devices, like wearables actually have a system ui.

BUG: 23822226

Change-Id: Ibc2d6c3b8db1de668b9cbced3efcec5a7a39f20b

services/core/java/com/android/server/BluetoothManagerService.java

@@ -273,7 +273,8 @@ class BluetoothManagerService extends IBluetoothManager.Stub {
             sysUiUid = mContext.getPackageManager().getPackageUid("com.android.systemui",
                     UserHandle.USER_OWNER);
         } catch (PackageManager.NameNotFoundException e) {
-            Log.wtf(TAG, "Unable to resolve SystemUI's UID.", e);
+            // Some platforms, such as wearables do not have a system ui.
+            Log.w(TAG, "Unable to resolve SystemUI's UID.", e);
         }
         mSystemUiUid = sysUiUid;
     }