Avoid media transcode can be bypass guard of developer options

When developer options switch is off, a user including guest user
can still configure media transcoding settings via slices.

Bug: 244569778
Test: manual
Change-Id: I3d70045c2498e683bf615cbe521e2f98d50b7eec

src/com/android/settings/development/transcode/TranscodeDefaultOptionPreferenceController.java

@@ -21,6 +21,7 @@ import android.os.SystemProperties;
 
 import com.android.settings.R;
 import com.android.settings.core.TogglePreferenceController;
+import com.android.settingslib.development.DevelopmentSettingsEnabler;
 
 /**
  * The controller (on the transcode settings screen) indicating that by default we assume that apps
@@ -47,7 +48,11 @@ public class TranscodeDefaultOptionPreferenceController extends TogglePreference
 
     @Override
     public int getAvailabilityStatus() {
-        return AVAILABLE;
+        if (DevelopmentSettingsEnabler.isDevelopmentSettingsEnabled(mContext)) {
+            return AVAILABLE;
+        } else {
+            return CONDITIONALLY_UNAVAILABLE;
+        }
     }
 
     @Override