Unbreak obtaining symmetric keys from AndroidKeyStore.

This tracks 59f977c6988e21b3b8aa6c83428bd6ee1a98816d due to which
AndroidKeyStore is unable to provide symmetric keys because it
assumes that the digest field is not repeating.

Bug: 18088752
Change-Id: Ie8ed01449280b7c759e81aeaf2066953b0abaf2a
1 file changed