Keystore 2.0: Add safe crypto wrapper

 * Adds safe wrappers for AES_gcm_decrypt and AES_gcm_encrypt.
 * Adds AES256 key generation.
 * Adds ZVec, a simple fixed size owned vector type that locks
   the backing memory in place with mlock and zeroes the buffer
   before freeing it.

Test: keystore2_test
Bug: 173545997
Change-Id: Id7e30d50b024da1fa8aa58a07cd9bb7a861f81f0
diff --git a/keystore2/src/crypto/TEST_MAPPING b/keystore2/src/crypto/TEST_MAPPING
new file mode 100644
index 0000000..f6fb97a
--- /dev/null
+++ b/keystore2/src/crypto/TEST_MAPPING
@@ -0,0 +1,10 @@
+{
+  "presubmit": [
+    {
+      "name": "keystore2_crypto_test_rust"
+    },
+    {
+      "name": "keystore2_crypto_test"
+    }
+  ]
+}