Use VERSION_CODES.R now that it's defined

This old todo can now be done (and could have for the last
2 years)

Test: NetworkStackTests
Bug: 149676685
Change-Id: Ide60adb75ec320653f8cc8c3806f0b26e56acb01
diff --git a/common/networkstackclient/src/android/net/networkstack/ModuleNetworkStackClient.java b/common/networkstackclient/src/android/net/networkstack/ModuleNetworkStackClient.java
index cbbae37..c3079fe 100644
--- a/common/networkstackclient/src/android/net/networkstack/ModuleNetworkStackClient.java
+++ b/common/networkstackclient/src/android/net/networkstack/ModuleNetworkStackClient.java
@@ -44,9 +44,7 @@
      */
     @NonNull
     public static synchronized ModuleNetworkStackClient getInstance(Context packageContext) {
-        // TODO(b/149676685): change this check to "< R" once R is defined
-        if (SDK_INT < Build.VERSION_CODES.Q
-                || (SDK_INT == Build.VERSION_CODES.Q && "REL".equals(Build.VERSION.CODENAME))) {
+        if (SDK_INT < Build.VERSION_CODES.R) {
             // The NetworkStack connector is not available through NetworkStack before R
             throw new UnsupportedOperationException(
                     "ModuleNetworkStackClient is not supported on API " + SDK_INT);