[Ruby] Added Support for Building Models from Hashes with Strings as Keys

Created by: ckoegel

When attempting to build ruby objects from hashes using the build_from_hash function, the object will only be built properly if the hash (attributes) uses Symbols for keys. In some use cases, users may want to build objects from hashes that use Strings as keys, such as when the default settings for JSON.parse are used. JSON.parse has an option symbolize_names that can be used to accomplish this, but with this PR, the generated SDK will now attempt to convert all hashes to use Symbols as keys.

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  ./bin/utils/export_docs_generators.sh

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