Enable Carrier-Config cache for Settings

- Since the "Mobile-Data Details Settings" (NETWORK_OPERATOR_SETTINGS) will query Carrier-Config around 70 times during launching, use the Carrier-Config cache to reduce 69 times to speed up the launching time.

- It takes about 3ms to query a Carrier-Config each time.

- Create a singleton class to share the Carrier-Config for all
sub-settings.

Bug: 204135235
Test: manual test
atest -c ApnPreferenceControllerTest \
         AutoSelectPreferenceControllerTest \
         BackupCallingPreferenceControllerTest \
         CarrierConfigCacheTest \
         CarrierPreferenceControllerTest \
         CarrierSettingsVersionPreferenceControllerTest \
         DataServiceSetupPreferenceControllerTest \
         Enable2gPreferenceControllerTest \
         EnabledNetworkModePreferenceControllerTest \
         Enhanced4gBasePreferenceControllerTest \
         MobileNetworkUtilsTest \
         NetworkProviderBackupCallingGroupTest \
         NrAdvancedCallingPreferenceControllerTest \
         PreferredNetworkModePreferenceControllerTest \
         TelephonyTogglePreferenceControllerTest \
         WifiPickerTrackerHelperTest
make RunSettingsRoboTests \
     ROBOTEST_FILTER=ContactDiscoveryPreferenceControllerTest
make RunSettingsRoboTests \
     ROBOTEST_FILTER=VideoCallingPreferenceControllerTest

Change-Id: I26f9ac115a754910b5d59e820703f1a0e701bb7f

src/com/android/settings/network/telephony/CarrierPreferenceController.java

@@ -28,17 +28,19 @@ import android.telephony.SubscriptionManager;
 import androidx.annotation.VisibleForTesting;
 import androidx.preference.Preference;
 
+import com.android.settings.network.CarrierConfigCache;
+
 /**
  * Preference controller for "Carrier Settings"
  */
 public class CarrierPreferenceController extends TelephonyBasePreferenceController {
 
     @VisibleForTesting
-    CarrierConfigManager mCarrierConfigManager;
+    CarrierConfigCache mCarrierConfigCache;
 
     public CarrierPreferenceController(Context context, String key) {
         super(context, key);
-        mCarrierConfigManager = context.getSystemService(CarrierConfigManager.class);
+        mCarrierConfigCache = CarrierConfigCache.getInstance(context);
     }
 
     public void init(int subId) {
@@ -47,7 +49,7 @@ public class CarrierPreferenceController extends TelephonyBasePreferenceControll
 
     @Override
     public int getAvailabilityStatus(int subId) {
-        final PersistableBundle carrierConfig = mCarrierConfigManager.getConfigForSubId(subId);
+        final PersistableBundle carrierConfig = mCarrierConfigCache.getConfigForSubId(subId);
 
         // Return available if it is in CDMA or GSM mode, and the flag is on
         return carrierConfig != null
@@ -72,7 +74,7 @@ public class CarrierPreferenceController extends TelephonyBasePreferenceControll
     }
 
     private Intent getCarrierSettingsActivityIntent(int subId) {
-        final PersistableBundle config = mCarrierConfigManager.getConfigForSubId(subId);
+        final PersistableBundle config = mCarrierConfigCache.getConfigForSubId(subId);
         final ComponentName cn = ComponentName.unflattenFromString(
                 config == null ? "" : config.getString(
                         CarrierConfigManager.KEY_CARRIER_SETTINGS_ACTIVITY_COMPONENT_NAME_STRING,