Fix tel number parsing crash

UrlUtilities.getTelNumber crash if the url param does not contain ":",
add a check to the function preventing from crash.

Bug: 830086
Change-Id: Icb82df469986f329a5fdaf6ce3b20624a0530acb
Reviewed-on: https://chromium-review.googlesource.com/1091885
Commit-Queue: Lei Tian <ltian@chromium.org>
Reviewed-by: Theresa <twellington@chromium.org>
Cr-Commit-Position: refs/heads/master@{#565456}

chrome/android/java/src/org/chromium/chrome/browser/util/UrlUtilities.java

@@ -65,6 +65,7 @@ public class UrlUtilities {
      *         guaranteed.
      */
     public static String getTelNumber(String uri) {
+        if (uri == null || !uri.contains(":")) return "";
         return uri.split(":")[1];
     }