Consider caching cryptographic primitives

[mottljan]

Getting/creating keysets and initializing cryptographic primitives (e.g. StraemingAead) using those keysets should be ideally done just once per process as stated in the docs of AndroidKeysetManager class. Currently we do this per creation of the instance of any type using Tink under the hood (EncryptedFile, EncryptedSharedPreferences, both encrypted DataStores). This behavior stayed the same since Jetpack Security implementation, so it probably is not a big deal. However, it still might be a place for improvement to optimize this as described in Tink documentation, if possible.