Due to an internal issue, some code from objective-c folder was copied
into objective_c .
Trying to undo that.
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Upgrade apple platform deployment_target versions to fix the cocoapods
push of BoringSSL-GRPC about the following error:
```
ld: file not found: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/arc/libarclite_macosx.a
clang: error: linker command failed with exit code 1 (use -v to see invocation)
```
ref: https://developer.apple.com/forums/thread/725300
This also aligns with the versions required by
[protobuf](https://github.com/protocolbuffers/protobuf/pull/10652)
```
ios.deployment_target = '10.0'
osx.deployment_target = '10.12'
tvos.deployment_target = '12.0'
watchos.deployment_target = '6.0'
```
* Fix all lint errors in repo.
* Use strict buildifier by default
* Whoops. That file does not exist
* Attempt fix to buildifier invocation
* Add missing copyright
It’s the magic sentence that allows pods dependent on RxLibrary to be
archived correctly by XCode.
It’s less than ideal, and seems arbitrary (why RxLibrary specifically?),
so we’ll try to produce a minimal case and open an issue with it in the
Cocoapods repo.