Administration: Define the $title global on privacy screens.

This brings more consistency with other screens and avoids a PHP warning in `get_plugin_page_hookname()`:
{{{
preg_replace(): Passing null to parameter #3 ($subject) of type array|string is deprecated
}}}

Props ipajen, jrf, SergeyBiryukov.
Fixes #57578.

git-svn-id: https://develop.svn.wordpress.org/trunk@55263 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-admin/erase-personal-data.php

@@ -13,6 +13,9 @@ if ( ! current_user_can( 'erase_others_personal_data' ) || ! current_user_can( '
 	wp_die( __( 'Sorry, you are not allowed to erase personal data on this site.' ) );
 }
 
+// Used in the HTML title tag.
+$title = __( 'Erase Personal Data' );
+
 // Contextual help - choose Help on the top right of admin panel to preview this.
 get_current_screen()->add_help_tab(
 	array(

src/wp-admin/export-personal-data.php

@@ -13,6 +13,9 @@ if ( ! current_user_can( 'export_others_personal_data' ) ) {
 	wp_die( __( 'Sorry, you are not allowed to export personal data on this site.' ) );
 }
 
+// Used in the HTML title tag.
+$title = __( 'Export Personal Data' );
+
 // Contextual help - choose Help on the top right of admin panel to preview this.
 get_current_screen()->add_help_tab(
 	array(

src/wp-admin/options-privacy.php

@@ -18,6 +18,9 @@ if ( isset( $_GET['tab'] ) && 'policyguide' === $_GET['tab'] ) {
 	return;
 }
 
+// Used in the HTML title tag.
+$title = __( 'Privacy' );
+
 add_filter(
 	'admin_body_class',
 	static function( $body_class ) {

src/wp-admin/privacy-policy-guide.php

@@ -17,6 +17,9 @@ if ( ! class_exists( 'WP_Privacy_Policy_Content' ) ) {
 	include_once ABSPATH . 'wp-admin/includes/class-wp-privacy-policy-content.php';
 }
 
+// Used in the HTML title tag.
+$title = __( 'Privacy Policy Guide' );
+
 add_filter(
 	'admin_body_class',
 	static function( $body_class ) {