Expose constants of ConnectivityManager

The callers cannot call the hidden APIs after ConnectivityManager
became a part of mainline module, so expose them for callers.
Also change the value of ACTION_PROMPT_PARTIAL_CONNECTIVITY,
ACTION_PROMPT_LOST_VALIDATION and ACTION_PROMPT_UNVALIDATED because
of API lint errors.

Bug: 172183305
Test: Check private DNS settings is normal, and test NO_INTERNET
      notification can be shown normally.
Change-Id: I715c766ad8e5eb54f4dc67239c1dbca7239506fc
diff --git a/framework/api/module-lib-current.txt b/framework/api/module-lib-current.txt
index 7a91f64..8e9e6ac 100644
--- a/framework/api/module-lib-current.txt
+++ b/framework/api/module-lib-current.txt
@@ -20,6 +20,9 @@
     method @RequiresPermission(android.Manifest.permission.NETWORK_STACK) public void setProfileNetworkPreference(@NonNull android.os.UserHandle, int, @Nullable java.util.concurrent.Executor, @Nullable Runnable);
     method @RequiresPermission(anyOf={android.Manifest.permission.MANAGE_TEST_NETWORKS, android.Manifest.permission.NETWORK_STACK}) public void simulateDataStall(int, long, @NonNull android.net.Network, @NonNull android.os.PersistableBundle);
     method public void systemReady();
+    field public static final String ACTION_PROMPT_LOST_VALIDATION = "android.net.action.PROMPT_LOST_VALIDATION";
+    field public static final String ACTION_PROMPT_PARTIAL_CONNECTIVITY = "android.net.action.PROMPT_PARTIAL_CONNECTIVITY";
+    field public static final String ACTION_PROMPT_UNVALIDATED = "android.net.action.PROMPT_UNVALIDATED";
     field public static final String PRIVATE_DNS_MODE_OFF = "off";
     field public static final String PRIVATE_DNS_MODE_OPPORTUNISTIC = "opportunistic";
     field public static final String PRIVATE_DNS_MODE_PROVIDER_HOSTNAME = "hostname";