Merges the encryptor creation between RyDE and Ghostryde.
The new file - RydeEncryption.java - is a merge of the removed functions in
Ghostryde.java and the RydePgpEncryptionOutputStream.java.
This is one of a series of CLs - each merging a single "part" of the encoding.
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=205246053
