Add CTS for systemReady() & getIpSecNetIdRange()

Bug: 182963354
Test: 1. atest CtsNetTestCases:ConnectivityManagerTest
      2. atest CtsNetTestCasesLatestSdk:ConnectivityManagerTest
Change-Id: I0b286f32389501402e552010546c62f3e56833d6
diff --git a/tests/cts/net/src/android/net/cts/ConnectivityManagerTest.java b/tests/cts/net/src/android/net/cts/ConnectivityManagerTest.java
index c1627c8..77a7199 100644
--- a/tests/cts/net/src/android/net/cts/ConnectivityManagerTest.java
+++ b/tests/cts/net/src/android/net/cts/ConnectivityManagerTest.java
@@ -2151,6 +2151,24 @@
                 null /* listener */));
     }
 
+    @Test
+    public void testSystemReady() {
+        assumeTrue(TestUtils.shouldTestSApis());
+        assertThrows(SecurityException.class, () -> mCm.systemReady());
+    }
+
+    @Test
+    public void testGetIpSecNetIdRange() {
+        assumeTrue(TestUtils.shouldTestSApis());
+        // The lower refers to ConnectivityManager.TUN_INTF_NETID_START.
+        final long lower = 64512;
+        // The upper refers to ConnectivityManager.TUN_INTF_NETID_START
+        // + ConnectivityManager.TUN_INTF_NETID_RANGE - 1
+        final long upper = 65535;
+        assertEquals(lower, (long) ConnectivityManager.getIpSecNetIdRange().getLower());
+        assertEquals(upper, (long) ConnectivityManager.getIpSecNetIdRange().getUpper());
+    }
+
     private void verifySettings(int expectedAirplaneMode, int expectedPrivateDnsMode,
             int expectedAvoidBadWifi) throws Exception {
         assertEquals(expectedAirplaneMode, Settings.Global.getInt(