fix(metadata-generator): Static frameworks from .o

[mbektchiev]

Take into account static frameworks composed of a single object file
such as GoogleMaps.

Fix taken from: NativeScript/ios@f34d4e9#diff-752cd2355f79b442571e27326e7bb4a6R251

PR Checklist

• The PR title follows our guidelines: https://github.com/NativeScript/NativeScript/blob/master/CONTRIBUTING.md#commit-messages.
• There is an issue for the bug/feature this PR is for. To avoid wasting your time, it's best to open a suggestion issue first and wait for approval before working on it.
• You have signed the CLA.
• All existing tests are passing: https://github.com/NativeScript/ios-runtime/blob/master/CONTRIBUTING.md#contribute-to-the-code-base
• Tests for the changes are included.

What is the current behavior?

refs NativeScript/ios#25