Enable strictmode logging in system_server & add a lock.

We weren't logging strictmode violation in the system_server process
in non-user builds (only system apps), even though the rest of the
strictmode logging supports it.

Also add a missing lock in ActivityManagerService.

Change-Id: If2af96a7e4fdde604a647b836097f0029ef1334b

services/java/com/android/server/SystemServer.java

@@ -517,6 +517,17 @@ class ServerThread extends Thread {
             }
         });
 
+        // For debug builds, log event loop stalls to dropbox for analysis.
+        // Similar logic also appears in ActivityThread.java for system apps.
+        if (!"user".equals(Build.TYPE)) {
+            Slog.i(TAG, "Enabling StrictMode for system server.");
+            StrictMode.setThreadPolicy(
+                StrictMode.DISALLOW_DISK_WRITE |
+                StrictMode.DISALLOW_DISK_READ |
+                StrictMode.DISALLOW_NETWORK |
+                StrictMode.PENALTY_DROPBOX);
+        }
+
         Looper.loop();
         Slog.d(TAG, "System ServerThread is exiting!");
     }