fix android ci from fbobjc_target_sdk_version (facebook#27919)

Summary:
fbobjc_target_sdk_version is not available in Buck used for OSS, and broke Android CI.

## Changelog

[Android] [Fixed] - Android CI dependency fetch
Pull Request resolved: facebook#27919

Test Plan: ./scripts/circleci/buck_fetch.sh will successfully run on CI,

Reviewed By: RSNara

Differential Revision: D19663699

Pulled By: fkgozali

fbshipit-source-id: c1f10cfad6c3415c876570139f1af2bcc9e56e4e

tools/build_defs/oss/rn_defs.bzl

@@ -65,7 +65,6 @@ def rn_xplat_cxx_library(name, **kwargs):
         for k, v in kwargs.items()
         if k.startswith("exported_")
     }
-    new_kwargs.setdefault("fbobjc_target_sdk_version", "10.0")
 
     native.cxx_library(
         name = name,