DnsException: run only on T+ versions

- Test was failing on S mainline builds. Fixing forward.

Bug: 210540375
Test: CtsDnsResolverTests.
Change-Id: Ia980965c8ee1b9ddae99f593628f8b7ecfeca394
diff --git a/tests/cts/net/src/android/net/cts/DnsResolverTest.java b/tests/cts/net/src/android/net/cts/DnsResolverTest.java
index 634665f..4992795 100644
--- a/tests/cts/net/src/android/net/cts/DnsResolverTest.java
+++ b/tests/cts/net/src/android/net/cts/DnsResolverTest.java
@@ -814,7 +814,7 @@
     }
 
     /** Verifies that DnsResolver.DnsException can be subclassed and its constructor re-used. */
-    @Test @IgnoreUpTo(Build.VERSION_CODES.R)
+    @Test @IgnoreUpTo(Build.VERSION_CODES.S)
     public void testDnsExceptionConstructor() throws InterruptedException {
         class TestDnsException extends DnsResolver.DnsException {
             TestDnsException(int code, @Nullable Throwable cause) {