Fine-tune launch time in Network & Internet settings

- Avoid creating WifiPickerTracker if Hotspot network feature is not enabled

Fix: 312905628
Test: unit test
atest -c InternetPreferenceControllerTest

Change-Id: I5818698ce06244aa7660e90a5f2fd372a3a221bf

tests/unit/src/com/android/settings/network/InternetPreferenceControllerTest.java

@@ -298,4 +298,11 @@ public class InternetPreferenceControllerTest {
 
         assertThat(mPreference.getSummary().toString()).isEqualTo(TEST_SUMMARY);
     }
+
+    @Test
+    public void updateHotspotNetwork_hotspotNetworkNotEnabled_returnFalse() {
+        mController.mWifiPickerTrackerHelper = null;
+
+        assertThat(mController.updateHotspotNetwork()).isFalse();
+    }
 }