Update docs for DELETE_PACKAGES permission.

        android:protectionLevel="signature|privileged" />

    <!-- @SystemApi Allows an application to delete packages.

    <p>Not for use by third-party applications. -->

         <p>Not for use by third-party applications.

         <p>Starting in {@link android.os.Build.VERSION_CODES#N}, user confirmation is requested

         when the application deleting the package is not the same application that installed the

         package. -->

    <permission android:name="android.permission.DELETE_PACKAGES"

        android:protectionLevel="signature|privileged" />