Messaging: Rename androidx.appcompat.mms

* Someone apparently decided to "Replace-In-Files" these before, but
  they are not correct according to the folder structure
* Since it is just annoying to read the code in AS when it does not
  match the folder, change the package name back

Change-Id: Iea5c51aeb9e1f5b650a1009348065c7c38cddbeb

src/com/android/messaging/sms/MmsSender.java

@@ -23,7 +23,7 @@ import android.content.Context;
 import android.content.Intent;
 import android.net.Uri;
 import android.os.Bundle;
-import androidx.appcompat.mms.MmsManager;
+import android.support.v7.mms.MmsManager;
 import android.telephony.SmsManager;
 
 import com.android.messaging.datamodel.MmsFileProvider;