Revert^2 "Nullability Annotations replacement"

This reverts commit 19d1d3d15d.

Reason for revert: revert it because this is not the root cause.

bug: 316867690
Change-Id: I0f168dbb64044aa720202af7b1040afd4f028c9c

src/com/android/settings/TrustedCredentialsDialogBuilder.java

@@ -15,7 +15,6 @@
  */
 package com.android.settings;
 
-import android.annotation.NonNull;
 import android.app.Activity;
 import android.app.admin.DevicePolicyManager;
 import android.content.DialogInterface;
@@ -31,6 +30,7 @@ import android.widget.Button;
 import android.widget.LinearLayout;
 import android.widget.Spinner;
 
+import androidx.annotation.NonNull;
 import androidx.appcompat.app.AlertDialog;
 
 import com.android.internal.widget.LockPatternUtils;