The header is missing from the file lists, resulting in incomplete installs.

This was originally contributed in https://github.com/google/leveldb/pull/568.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=189822907

Fixes https://github.com/google/leveldb/issues/466

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=189425354