Add CallManager registerPhone at GsmCdmaPhone

Fix: 173704265
Test: atest GsmCdmaPhoneTest (PASS)
Manual test: enable DSDS, then call *135#. (PASS)

Change-Id: Icaa76970f2ec390dc67583aca1af0a6266462940
diff --git a/src/java/com/android/internal/telephony/GsmCdmaPhone.java b/src/java/com/android/internal/telephony/GsmCdmaPhone.java
index d7b3b79..e3f51d3 100644
--- a/src/java/com/android/internal/telephony/GsmCdmaPhone.java
+++ b/src/java/com/android/internal/telephony/GsmCdmaPhone.java
@@ -314,6 +314,8 @@
                 EVENT_UICC_APPS_ENABLEMENT_SETTING_CHANGED, null, false);
 
         loadTtyMode();
+
+        CallManager.getInstance().registerPhone(this);
         logd("GsmCdmaPhone: constructor: sub = " + mPhoneId);
     }