Revert of Update build_ios_libs.py to new GN target names. (patchset #1 id:1 of https://codereview.webrtc.org/2888903002/ )

Reason for revert:
This depends on another CL that has been reverted.

Original issue's description:
> Update build_ios_libs.py to new GN target names.
>
> TBR=kjellander@webrtc.org
> NOTRY=true
> BUG=None
>
> Review-Url: https://codereview.webrtc.org/2888903002
> Cr-Commit-Position: refs/heads/master@{#18175}
> Committed: https://chromium.googlesource.com/external/webrtc/+/c3f110a1f9c53d84c70a89af5786c9fc33a8b71d

TBR=
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=None

Review-Url: https://codereview.webrtc.org/2886873007
Cr-Commit-Position: refs/heads/master@{#18183}
diff --git a/tools_webrtc/ios/build_ios_libs.py b/tools_webrtc/ios/build_ios_libs.py
index 412ad67..734f3e2 100755
--- a/tools_webrtc/ios/build_ios_libs.py
+++ b/tools_webrtc/ios/build_ios_libs.py
@@ -120,7 +120,7 @@
   if build_type == 'static_only':
     gn_target_name = 'rtc_sdk_objc'
   elif build_type == 'framework':
-    gn_target_name = 'objc_framework'
+    gn_target_name = 'rtc_sdk_framework_objc'
     if not use_bitcode:
       gn_args.append('enable_dsyms=true')
     gn_args.append('enable_stripping=true')