Make NONEwithECDSA truncate input when necessary.

Keymaster's implementation of ECDSA with digest NONE rejects input
longer than group size in bytes. RI's NONEwithECDSA accepts inputs
of arbitrary length by truncating them to the above size. This CL
makes Android Keystore's NONEwithECDSA do the truncation to keep
the JCA and Keymaster happy.

The change is inside AndroidKeyStoreECDSASignatureSpi$NONE. All other
small modifications are for supporting that change by making it
possible for AndroidKeyStoreSignatureSpiBase to pass in the signature
being verified into KeyStoreCryptoOperationStreamer. This in turn is
needed to make it possible for NONEwithECDSA implementation to provide
a wrapper streamer which truncates input.

Bug: 22030217
Change-Id: I26064f6df37ef8c631d70a36a356aa0b76a9ad29