Move ImsResolver to a singleton pattern

In order for dependencies in frameworks/opt/telephony to be
able to access ImsResolver, move ImsResolver to a singleton
pattern.

Bug: 188208808
Test: atest TeleServiceTests
Change-Id: I424461bfc7b2472193a023c85b760b5195421d42
diff --git a/src/com/android/phone/PhoneGlobals.java b/src/com/android/phone/PhoneGlobals.java
index da3b08d..130c775 100644
--- a/src/com/android/phone/PhoneGlobals.java
+++ b/src/com/android/phone/PhoneGlobals.java
@@ -157,7 +157,6 @@
     CallNotifier notifier;
     CallerInfoCache callerInfoCache;
     NotificationMgr notificationMgr;
-    ImsResolver mImsResolver;
     TelephonyRcsService mTelephonyRcsService;
     public PhoneInterfaceManager phoneMgr;
     public ImsRcsController imsRcsController;
@@ -408,10 +407,10 @@
                         R.string.config_ims_mmtel_package);
                 String defaultImsRcsPackage = getResources().getString(
                         R.string.config_ims_rcs_package);
-                mImsResolver = new ImsResolver(this, defaultImsMmtelPackage,
+                ImsResolver.make(this, defaultImsMmtelPackage,
                         defaultImsRcsPackage, PhoneFactory.getPhones().length,
                         new ImsFeatureBinderRepository());
-                mImsResolver.initialize();
+                ImsResolver.getInstance().initialize();
 
                 // With the IMS phone created, load static config.xml values from the phone process
                 // so that it can be provided to the ImsPhoneCallTracker.
@@ -564,10 +563,6 @@
         return PhoneFactory.getPhone(SubscriptionManager.getPhoneId(subId));
     }
 
-    public ImsResolver getImsResolver() {
-        return mImsResolver;
-    }
-
     /* package */ CallManager getCallManager() {
         return mCM;
     }
@@ -1033,7 +1028,7 @@
         pw.println("ImsResolver:");
         pw.increaseIndent();
         try {
-            if (mImsResolver != null) mImsResolver.dump(fd, pw, args);
+            if (ImsResolver.getInstance() != null) ImsResolver.getInstance().dump(fd, pw, args);
         } catch (Exception e) {
             e.printStackTrace();
         }