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/TelephonyTogglePreferenceController.java

@@ -19,10 +19,10 @@ package com.android.settings.network.telephony;
 import android.content.Context;
 import android.content.res.Resources;
 import android.os.PersistableBundle;
-import android.telephony.CarrierConfigManager;
 import android.telephony.SubscriptionManager;
 
 import com.android.settings.core.TogglePreferenceController;
+import com.android.settings.network.CarrierConfigCache;
 
 import java.util.concurrent.atomic.AtomicInteger;
 
@@ -82,9 +82,7 @@ public abstract class TelephonyTogglePreferenceController extends TogglePreferen
         if (!SubscriptionManager.isValidSubscriptionId(subId)) {
             return null;
         }
-        final CarrierConfigManager carrierConfigMgr =
-                mContext.getSystemService(CarrierConfigManager.class);
-        return carrierConfigMgr.getConfigForSubId(subId);
+        return CarrierConfigCache.getInstance(mContext).getConfigForSubId(subId);
     }
 
     /**