vendor: apns: Fix wrong IPV4 protocols

* The correct string is "IP", not "IPV4"
* Other possible values are "IPV6" or "IPV4V6"
* Source: prebuilts/sdk/30/public/api/android.txt
  Lines: 46832-46834

Change-Id: I3d4729b829f87a4d7ab83584d1aed01d87e10fd2