Disallow turning off developer options in page-agnostic mode

When device is in page-agnostic mode, it would be OEM unlocked and
filesystem will be different than production. Don't allow to turn
off developer options in that state.

Bug: 329657279
Bug: 295035851
Test: m Settings && adb install -r $ANDROID_PRODUCT_OUT/system_ext/priv-app/Settings/Settings.apk
Change-Id: I9b8a9dbaf8192bb3758c53501450eb45e2fe8d9c

src/com/android/settings/development/DevelopmentSettingsDashboardFragment.java

@@ -577,6 +577,15 @@ public class DevelopmentSettingsDashboardFragment extends RestrictedDashboardFra
         if (Utils.isMonkeyRunning()) {
             return;
         }
+
+        // Disabling developer options in page-agnostic mode isn't supported as device isn't in
+        // production state
+        if (Enable16kUtils.isPageAgnosticModeOn(getContext())) {
+            Enable16kUtils.showPageAgnosticWarning(getContext());
+            onDisableDevelopmentOptionsRejected();
+            return;
+        }
+
         DevelopmentSettingsEnabler.setDevelopmentSettingsEnabled(getContext(), false);
         final SystemPropPoker poker = SystemPropPoker.getInstance();
         poker.blockPokes();