Add new RIL commands to read/write NV items and reset NV config.

Add new RIL commands and generic code cleanups.

The only changes required for OMA DM support are the
addition of five new methods in ITelephony.aidl for
reading/writing NV items and performing NV config and
radio resets (requires MODIFY_PHONE_STATE), along with
the new RIL request IDs in RILConstants.java.

Bug: 12864208
Change-Id: I958d2571580d98a49936ef2e6822e5ac086acbe2

core/java/android/net/ConnectivityManager.java

@@ -800,6 +800,8 @@ public class ConnectivityManager {
      * Ensure that a network route exists to deliver traffic to the specified
      * host via the specified network interface. An attempt to add a route that
      * already exists is ignored, but treated as successful.
+     * <p>This method requires the caller to hold the permission
+     * {@link android.Manifest.permission#CHANGE_NETWORK_STATE}.
      * @param networkType the type of the network over which traffic to the specified
      * host is to be routed
      * @param hostAddress the IP address of the host to which the route is desired