CipherTest: add block and output size for OAEP

This asserts the block and output sizes for Cipher.RSA/ECB/OAEPPadding
and the specific message digest modes are correct.

Test: vogar --mode host --classpath out/host/common/obj/JAVA_LIBRARIES/core-tests-support-hostdex_intermediates/classes.jack --classpath out/host/common/obj/JAVA_LIBRARIES/core-tests-hostdex_intermediates/classes.jack libcore/luni/src/test/java/libcore/javax/crypto/CipherTest.java
Change-Id: I39c11f337bd4d618af9cc9f8d075990d68e50077