DO NOT MERGE Captive portal systel log improvements

This patch improves system logging around captive portal detection to
make inspection of bug reports sligthly easier:

- NetworkMonitor now logs by default CMD_CAPTIVE_PORTAL_RECHECK and
  CMD_CAPTIVE_PORTAL_APP_FINISHED. Other system logs are kept off with
  a new VDBG boolean contant,
- NetworkNotificationManager now prints the notification id at
  notification time. This allows to easily correlate show and clear.
- errors in NetworkNotificationManager are logged as Throwable instead
  of through their implicit toString() method.

Test: $ runtest frameworks-net
Bug: 32198726

(cherry picked from commit 8b025bf108c729156b40159038befa0e6c5bebce)

Change-Id: I7780c389a94c4b9fa226f53b02fe5960d1c08618
diff --git a/services/core/java/com/android/server/connectivity/NetworkMonitor.java b/services/core/java/com/android/server/connectivity/NetworkMonitor.java
index c73d1dd..aa66917 100644
--- a/services/core/java/com/android/server/connectivity/NetworkMonitor.java
+++ b/services/core/java/com/android/server/connectivity/NetworkMonitor.java
@@ -80,7 +80,8 @@
  */
 public class NetworkMonitor extends StateMachine {
     private static final String TAG = NetworkMonitor.class.getSimpleName();
-    private static final boolean DBG = false;
+    private static final boolean DBG  = true;
+    private static final boolean VDBG = false;
 
     // Default configuration values for captive portal detection probes.
     // TODO: append a random length parameter to the default HTTPS url.
@@ -918,7 +919,7 @@
                     latencyBroadcast.putExtra(EXTRA_SSID, currentWifiInfo.getSSID());
                     latencyBroadcast.putExtra(EXTRA_BSSID, currentWifiInfo.getBSSID());
                 } else {
-                    if (DBG) logw("network info is TYPE_WIFI but no ConnectionInfo found");
+                    if (VDBG) logw("network info is TYPE_WIFI but no ConnectionInfo found");
                     return;
                 }
                 break;
@@ -931,8 +932,8 @@
                     if (cellInfo.isRegistered()) {
                         numRegisteredCellInfo++;
                         if (numRegisteredCellInfo > 1) {
-                            log("more than one registered CellInfo.  Can't " +
-                                    "tell which is active.  Bailing.");
+                            if (VDBG) logw("more than one registered CellInfo." +
+                                    " Can't tell which is active.  Bailing.");
                             return;
                         }
                         if (cellInfo instanceof CellInfoCdma) {
@@ -948,7 +949,7 @@
                             CellIdentityWcdma cellId = ((CellInfoWcdma) cellInfo).getCellIdentity();
                             latencyBroadcast.putExtra(EXTRA_CELL_ID, cellId);
                         } else {
-                            if (DBG) logw("Registered cellinfo is unrecognized");
+                            if (VDBG) logw("Registered cellinfo is unrecognized");
                             return;
                         }
                     }