Make isRebootRequiredForModemConfigChange SystemApi
and set the default as true

Bug: 124074656
Bug: 124115914
Test: build
Change-Id: I7be55a554a62a37bcf66fdc558186735715bb982
diff --git a/src/com/android/phone/PhoneInterfaceManager.java b/src/com/android/phone/PhoneInterfaceManager.java
index e251516..c70eb60 100755
--- a/src/com/android/phone/PhoneInterfaceManager.java
+++ b/src/com/android/phone/PhoneInterfaceManager.java
@@ -6521,7 +6521,7 @@
 
     /**
      * Get whether reboot is required or not after making changes to modem configurations.
-     * Return value defaults to false
+     * Return value defaults to true
      */
     @Override
     public boolean isRebootRequiredForModemConfigChange() {