Remove +api from internal DEPS files.

This is redundant with [1].

[1] - https://cs.chromium.org/chromium/src/third_party/webrtc/DEPS?l=1424&rcl=914acd7589c3a31d8f99932b9c9a1917af2aa70f

Bug: webrtc:10244
No-Try: True
Change-Id: I447a9cb4187020d0ed74a2729b85d7924993cc70
Reviewed-on: https://webrtc-review.googlesource.com/c/119924
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#26422}

sdk/objc/DEPS

@@ -3,7 +3,6 @@ include_rules = [
   "+components",
   "+helpers",
   "+sdk",
-  "+api",
   "+common_video/h264",
   "+common_video/include",
   "+common_video/libyuv/include",