Make num-retries default a string.

TBR=phoglund@webrtc.org

Bug: chromium:755660
Change-Id: I770a79a78721a312b603aec40d23689245a48001
Reviewed-on: https://webrtc-review.googlesource.com/61343
Reviewed-by: Edward Lemur <ehmaldonado@webrtc.org>
Commit-Queue: Edward Lemur <ehmaldonado@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#22392}
diff --git a/examples/androidtests/video_quality_loopback_test.py b/examples/androidtests/video_quality_loopback_test.py
index 66a981b..b95f99f 100755
--- a/examples/androidtests/video_quality_loopback_test.py
+++ b/examples/androidtests/video_quality_loopback_test.py
@@ -86,7 +86,7 @@
   parser.add_argument('--temp_dir',
       help='A temporary directory to put the output.')
   parser.add_argument('--adb-path', help='Path to adb binary.', default='adb')
-  parser.add_argument('--num-retries', default=0,
+  parser.add_argument('--num-retries', default='0',
                       help='Number of times to retry the test on Android.')
   parser.add_argument('--isolated-script-test-perf-output',
       help='Where to store perf results in chartjson format.', default=None)