Toast warning message when non-admin user tries to open dev options.

Developer Settings are only accessible for the Admin users. Added a new toast warning message to be displayed when a non-admin user tries to open the Developer options.

Bug: 259941142
Test: Manually verfied by tapping on the USB debugging option from a Secondary user.
Change-Id: Ibd1b8e19d9130982982ee13ac98cbc1d8f5b8835
diff --git a/res/values/strings.xml b/res/values/strings.xml
index 402f526..eba04c0 100644
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -41,9 +41,13 @@
     <!-- [CHAR LIMIT=NONE] Device Info screen. Okay we get it, stop pressing, you already have it on -->
     <string name="show_dev_already">No need, you are already a developer.</string>
 
-    <!-- [CHAR LIMIT=NONE] Toast message when user attemps to launch developer otions before enabling it. -->
+    <!-- [CHAR LIMIT=NONE] Toast message when user attempts to launch developer options before enabling it. -->
     <string name="dev_settings_disabled_warning">Please enable developer options first.</string>
 
+    <!-- [CHAR LIMIT=NONE] Toast message when non-admin user attempts to launch developer options. -->
+    <string name="dev_settings_available_to_admin_only_warning">Only the admin users can access developer settings.</string>
+
+
     <!-- Category headings in left-pane header menu --> <skip />
     <!-- Settings main menu category heading. System (Updates, data, accessibility, about phone). [CHAR LIMIT=40] -->
     <string name="header_category_system">System</string>
diff --git a/src/com/android/settings/development/DevelopmentSettingsDashboardFragment.java b/src/com/android/settings/development/DevelopmentSettingsDashboardFragment.java
index e841eac..ff465a3 100644
--- a/src/com/android/settings/development/DevelopmentSettingsDashboardFragment.java
+++ b/src/com/android/settings/development/DevelopmentSettingsDashboardFragment.java
@@ -233,7 +233,14 @@
             return;
         }
         Context context = requireContext();
-        if (!DevelopmentSettingsEnabler.isDevelopmentSettingsEnabled(context)) {
+        UserManager um = (UserManager) getSystemService(Context.USER_SERVICE);
+
+        if (!um.isAdminUser()) {
+            Toast.makeText(context, R.string.dev_settings_available_to_admin_only_warning,
+                            Toast.LENGTH_SHORT)
+                    .show();
+            finish();
+        } else if (!DevelopmentSettingsEnabler.isDevelopmentSettingsEnabled(context)) {
             Toast.makeText(context, R.string.dev_settings_disabled_warning, Toast.LENGTH_SHORT)
                     .show();
             finish();