title: NullPointerException exception when trying to set title size on AlertDialog
body: <p>In AlertDialog, I am able to set size of Message but when I perform the same for Title it crashes.</p>
  
  <p>code:</p>
  
  <pre><code>AlertDialog dialog = new AlertDialog.Builder(this).setMessage(message).setTitle(title)
                 .setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener() {
                     public void onClick(DialogInterface dialog, int id) {
                        dialog.cancel();
                     }
                 }).show();
       TextView titleTxt= (TextView)dialog.findViewById(android.R.id.title);
       **titleTxt.setTextSize(TypedValue.COMPLEX_UNIT_SP, 40);** // crash here 
       TextView textView = (TextView) dialog.findViewById(android.R.id.message);
       **textView.setTextSize(40);** // works fine
  
  
  
   Button btn1 = dialog.getButton(DialogInterface.BUTTON_POSITIVE);
     btn1.setTextSize(36); 
  </code></pre>
  
  <p>My output:</p>
  
  <pre><code>05-10 11:49:56.917: E/AndroidRuntime(8376): FATAL EXCEPTION: main
  05-10 11:49:56.917: E/AndroidRuntime(8376): java.lang.NullPointerException
  05-10 11:49:56.917: E/AndroidRuntime(8376):     at com.binary.taxitop.LoginScreen.showAlertDialog(LoginScreen.java:116)
  05-10 11:49:56.917: E/AndroidRuntime(8376):     at com.binary.taxitop.LoginScreen.VerifyCredentialsAndEnterNextScreen(LoginScreen.java:103)
  05-10 11:49:56.917: E/AndroidRuntime(8376):     at com.binary.taxitop.LoginScreen.onClick(LoginScreen.java:84)
  05-10 11:49:56.917: E/AndroidRuntime(8376):     at android.view.View.performClick(View.java:3511)
  05-10 11:49:56.917: E/AndroidRuntime(8376):     at android.view.View$PerformClick.run(View.java:14109)
  05-10 11:49:56.917: E/AndroidRuntime(8376):     at android.os.Handler.handleCallback(Handler.java:605)
  05-10 11:49:56.917: E/AndroidRuntime(8376):     at android.os.Handler.dispatchMessage(Handler.java:92)
  05-10 11:49:56.917: E/AndroidRuntime(8376):     at android.os.Looper.loop(Looper.java:137)
  05-10 11:49:56.917: E/AndroidRuntime(8376):     at android.app.ActivityThread.main(ActivityThread.java:4424)
  05-10 11:49:56.917: E/AndroidRuntime(8376):     at java.lang.reflect.Method.invokeNative(Native Method)
  05-10 11:49:56.917: E/AndroidRuntime(8376):     at java.lang.reflect.Method.invoke(Method.java:511)
  05-10 11:49:56.917: E/AndroidRuntime(8376):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
  05-10 11:49:56.917: E/AndroidRuntime(8376):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
  05-10 11:49:56.917: E/AndroidRuntime(8376):     at dalvik.system.NativeStart.main(Native Method)
  </code></pre>
  
  <p>Thanks in advance.</p>