Clean up unused NetworkPolicyEditor

From DataUsageSummaryPreferenceController.

NetworkPolicyEditor.read() is not called, so
NetworkPolicyEditor.getPolicy() will always returns null.

Data limit info is already set in getDataUsageInfo().

Bug: 295260929
Test: robo test
Change-Id: I56a40cc906aa95207785886e704b1a59ea344e9c

tests/robotests/src/com/android/settings/datausage/DataUsageSummaryPreferenceControllerTest.java

@@ -47,7 +47,6 @@ import com.android.internal.logging.nano.MetricsProto;
 import com.android.settings.testutils.FakeFeatureFactory;
 import com.android.settings.testutils.shadow.ShadowEntityHeaderController;
 import com.android.settings.widget.EntityHeaderController;
-import com.android.settingslib.NetworkPolicyEditor;
 import com.android.settingslib.core.lifecycle.Lifecycle;
 import com.android.settingslib.net.DataUsageController;
 
@@ -87,8 +86,6 @@ public class DataUsageSummaryPreferenceControllerTest {
     @Mock
     private DataUsageSummaryPreference mSummaryPreference;
     @Mock
-    private NetworkPolicyEditor mPolicyEditor;
-    @Mock
     private NetworkTemplate mNetworkTemplate;
     @Mock
     private SubscriptionInfo mSubscriptionInfo;
@@ -145,7 +142,6 @@ public class DataUsageSummaryPreferenceControllerTest {
                 mDataUsageController,
                 mDataInfoController,
                 mNetworkTemplate,
-                mPolicyEditor,
                 mActivity, null, null, null, mDefaultSubscriptionId));
         doReturn(null).when(mController).getSubscriptionInfo(
                 SubscriptionManager.INVALID_SUBSCRIPTION_ID);
@@ -372,7 +368,6 @@ public class DataUsageSummaryPreferenceControllerTest {
                 mDataUsageController,
                 mDataInfoController,
                 mNetworkTemplate,
-                mPolicyEditor,
                 mActivity, mLifecycle, mHeaderController, mPreferenceFragment,
                 mDefaultSubscriptionId));