Align main thread checking by calling ThreadUtils

Since ThreadUtils encapsules method to ensure main thread, it is
suggested to call this method rather than maintaining our copy.

Bug: 258270052
Test: atest and manual.
Change-Id: I4c5fcdd6e5bcc7d1d08f526eedb3aa123926d8a1

src/com/android/settings/network/EthernetTetherPreferenceController.java

@@ -26,6 +26,7 @@ import androidx.lifecycle.Lifecycle;
 import androidx.lifecycle.OnLifecycleEvent;
 
 import com.android.internal.annotations.VisibleForTesting;
+import com.android.settingslib.utils.ThreadUtils;
 
 import java.util.HashSet;
 
@@ -74,7 +75,7 @@ public final class EthernetTetherPreferenceController extends TetherBasePreferen
 
     @Override
     public boolean shouldEnable() {
-        ensureRunningOnMainLoopThread();
+        ThreadUtils.ensureMainThread();
         String[] available = mTm.getTetherableIfaces();
         for (String s : available) {
             if (mAvailableInterfaces.contains(s)) {
@@ -94,11 +95,4 @@ public final class EthernetTetherPreferenceController extends TetherBasePreferen
         return TetheringManager.TETHERING_ETHERNET;
     }
 
-    private void ensureRunningOnMainLoopThread() {
-        if (Looper.getMainLooper().getThread() != Thread.currentThread()) {
-            throw new IllegalStateException(
-                    "Not running on main loop thread: "
-                            + Thread.currentThread().getName());
-        }
-    }
 }