Throw exception in Java if log tag or message is null

Change-Id: If1d2cefcdf5441381bd6c06416cab24883d31481
Bug: webrtc:9357
Reviewed-on: https://webrtc-review.googlesource.com/80963
Commit-Queue: Paulina Hensman <phensman@webrtc.org>
Reviewed-by: Magnus Jedvert <magjed@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#23510}

rtc_base/java/src/org/webrtc/Logging.java

@@ -88,6 +88,9 @@ public class Logging {
   }
 
   public static void log(Severity severity, String tag, String message) {
+    if (tag == null || message == null) {
+      throw new IllegalArgumentException("Logging tag or message may not be null.");
+    }
     if (loggingEnabled) {
       nativeLog(severity.ordinal(), tag, message);
       return;