Fix encryption/decryption of large blocks.

There's a long-standing bug (since ~Marshmallow) that causes
AndroidKeyStore to truncate large (>64 KiB) blocks of data.  This can
be avoided by callers by processing data in smaller chunks, and
smaller chunks are more memory-efficient while not being much (if any)
more time-efficient.  But, Keystore should handle large blocks
correctly.  This CL adds a test to all block cipher tests that
attempts to encrypt and then decrypt a 100 KiB block.

Bug: 123391046
Test:  CtsKeystoreTestCases
Change-Id: I0c0286fd5360d4fe62cbd8130aa0c17f97318801