Ignore iOS SDK during presubmit.

NOTRY=True

Review-Url: https://codereview.webrtc.org/1836663002
Cr-Commit-Position: refs/heads/master@{#13618}
diff --git a/PRESUBMIT.py b/PRESUBMIT.py
index 1ece201..9d813b1 100755
--- a/PRESUBMIT.py
+++ b/PRESUBMIT.py
@@ -418,6 +418,7 @@
   # they do not follow C++ lint rules.
   black_list = input_api.DEFAULT_BLACK_LIST + (
     r".*\bobjc[\\\/].*",
+    r"webrtc\/build\/ios\/SDK\/.*",
   )
   source_file_filter = lambda x: input_api.FilterSourceFile(x, None, black_list)
   results.extend(_CheckApprovedFilesLintClean(