Revert "Revert "Fix test case fail""

This reverts commit 75261d01dfe443238a118ba92853ec0d0519710b.

Reason for revert: roll forward

Change-Id: I0b66ba4ea918baf54ae084f6281c172a07b160b2
diff --git a/src/com/android/settings/core/InstrumentedPreferenceFragment.java b/src/com/android/settings/core/InstrumentedPreferenceFragment.java
index cafef00..f5f245f 100644
--- a/src/com/android/settings/core/InstrumentedPreferenceFragment.java
+++ b/src/com/android/settings/core/InstrumentedPreferenceFragment.java
@@ -22,6 +22,7 @@
 import android.util.Log;
 
 import androidx.annotation.XmlRes;
+import androidx.preference.Preference;
 import androidx.preference.PreferenceScreen;
 
 import com.android.settings.overlay.FeatureFactory;
@@ -78,6 +79,14 @@
         updateActivityTitleWithScreenTitle(getPreferenceScreen());
     }
 
+    @Override
+    public <T extends Preference> T findPreference(CharSequence key) {
+        if (key == null) {
+            return null;
+        }
+        return super.findPreference(key);
+    }
+
     protected final Context getPrefContext() {
         return getPreferenceManager().getContext();
     }