Remove shadow from "Apps and Notifications"

- Also create a util method to reuse it in different class.

Test: visual
Fixes: 128437380
Change-Id: I0e136feed3aead8c37e381095daebded55ef298d

tests/robotests/src/com/android/settings/UtilsTest.java

@@ -28,6 +28,8 @@ import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
+import android.app.ActionBar;
+import android.app.Activity;
 import android.app.admin.DevicePolicyManager;
 import android.content.ComponentName;
 import android.content.Context;
@@ -51,15 +53,18 @@ import android.os.storage.StorageManager;
 import android.os.storage.VolumeInfo;
 import android.util.IconDrawableFactory;
 import android.widget.EditText;
+import android.widget.ScrollView;
 import android.widget.TextView;
 
 import androidx.core.graphics.drawable.IconCompat;
+import androidx.fragment.app.FragmentActivity;
 
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.mockito.Mock;
 import org.mockito.MockitoAnnotations;
+import org.robolectric.Robolectric;
 import org.robolectric.RobolectricTestRunner;
 import org.robolectric.RuntimeEnvironment;
 
@@ -259,4 +264,21 @@ public class UtilsTest {
     public void isPackageEnabled_noApp_returnFalse() {
         assertThat(Utils.isPackageEnabled(mContext, PACKAGE_NAME)).isFalse();
     }
+
+    @Test
+    public void setActionBarShadowAnimation_nullParameters_shouldNotCrash() {
+        // no crash here
+        Utils.setActionBarShadowAnimation(null, null, null);
+    }
+
+    @Test
+    public void setActionBarShadowAnimation_shouldSetElevationToZero() {
+        final FragmentActivity activity = Robolectric.setupActivity(FragmentActivity.class);
+        final ActionBar actionBar = activity.getActionBar();
+
+        Utils.setActionBarShadowAnimation(activity, activity.getLifecycle(),
+                new ScrollView(mContext));
+
+        assertThat(actionBar.getElevation()).isEqualTo(0.f);
+    }
 }