Fix not allowing custom bundle_name

[luispadron]

Broken in https://github.com/bazel-ios/rules_ios/pull/754, this fixes by taking the given bundle_name or the name if not provided

[luispadron]

What command needs to be run to re-generate the Xcode projects? It seems like whatever I do it breaks the diff test because of arm64 paths:

arch -arch x86_64 /bin/bash -l -c "./tests/xcodeproj-tests.sh --update"

From:

https://github.com/bazel-ios/rules_ios/blob/master/tests/xcodeproj-tests.sh#L86-L92

[thiagohmcruz]

What command needs to be run to re-generate the Xcode projects? It seems like whatever I do it breaks the diff test because of arm64 paths:

arch -arch x86_64 /bin/bash -l -c "./tests/xcodeproj-tests.sh --update"

From:

https://github.com/bazel-ios/rules_ios/blob/master/tests/xcodeproj-tests.sh#L86-L92

This works:

arch -arch x86_64 /bin/bash -l -c "./tests/xcodeproj-tests.sh --update"

but it has some caveats:

• On Apple Silicon make sure your bazelisk is a FAT binary (e.g. https://github.com/bazelbuild/bazelisk/releases/download/v1.17.0/bazelisk-darwin).
• Since tests/xcodeproj-tests.sh uses bash make sure your PATH variable is configured such that the FAT bazelisk's path comes first:

  
  # line from my ~/.bashrc
  export PATH=$HOME/bin:/usr/local/bin:$PATH 

because my bazelisk is placed here (from which bazelisk)

/usr/local/bin/bazelisk

I just ran that command from `master` and it noop-ed for me as expected.