Update OEMCrypto documents

Merge from Widevine repo of http://go/wvgerrit/97763

There were no function signature changes, so the API version number
did not change from 16.2. There were several grammar and spelling
errors. There were also the following corrections:

1. The description of OEMCrypto_LoadProvisioning now says that devices
with a keybox use keys derived from the keybox device key, and devices
using Provisioning 3.0 use keys derived from the session key. The
description was previously reversed.

2. The function OEMCrypto_SupportedPatterns is no longer
discussed. This function was never fully defined.

3. The function OEMCrypto_LoadRenewal no longer says that keys and key
control blocks should be verified. This is because the function
OEMCrypto_LoadRenewal processes a message with no key control
block. It should update timers for the entire license.

Test: doc and comment change only
Bug: 153731804
Change-Id: I11a3069fcdbf67b369e2e2bc3fea8c08842eeb7b

libwvdrmengine/oemcrypto/include/OEMCryptoCENC.h

@@ -1036,8 +1036,8 @@ OEMCryptoResult OEMCrypto_PrepAndSignRenewalRequest(
  *   in the document "Widevine Core Message Serialization", to prepare the core
  *   message. If it returns an error, the error should be returned by OEMCrypto
  *   to the CDM layer. If it returns OEMCrypto_SUCCESS, then OEMCrypto shall
- *   sign compute the signature of the entire message. The entire message is
- *   the buffer starting at message with length message_length.
+ *   compute the signature of the entire message. The entire message is the
+ *   buffer starting at message with length message_length.
  *
  *   For a device that has a keybox, i.e. Provisioning 2.0, OEMCrypto will sign
  *   the request with the session's derived client mac key from the previous
@@ -1838,26 +1838,11 @@ OEMCryptoResult OEMCrypto_RefreshKeys(
  *   the session.
  *
  * Verification:
- *   The following checks should be performed. If any check fails, an error is
- *   returned, and none of the keys are loaded.
- *     1. The signature of the message shall be computed using mac_key[server],
- *        and the API shall verify the computed signature matches the signature
- *        passed in.  If not, return OEMCrypto_ERROR_SIGNATURE_FAILURE. The
- *        signature verification shall use a constant-time algorithm (a
- *        signature mismatch will always take the same time as a successful
- *        comparison).
- *     2. The API shall verify that each substring in each KeyObject has zero
- *        length or satisfies the range check described in the discussion of
- *        OEMCrypto_LoadKeys. If not, return OEMCrypto_ERROR_INVALID_CONTEXT.
- *     3. Each key's control block shall have a valid verification field. If
- *        not, return OEMCrypto_ERROR_INVALID_CONTEXT.
- *     4. If the key control block has the Nonce_Enabled bit set, the Nonce
- *        field shall match one of the nonces in the cache.  If not, return
- *        OEMCrypto_ERROR_INVALID_NONCE. If there is a match, remove that nonce
- *        from the cache.   Note that all the key control blocks in a
- *        particular call shall have the same nonce value.
- *     5. If a key ID is specified, and that key has not been loaded into this
- *        session, return OEMCrypto_ERROR_NO_CONTENT_KEY.
+ *   The signature of the message shall be computed using mac_key[server], and
+ *   the API shall verify the computed signature matches the signature passed
+ *   in. If not, return OEMCrypto_ERROR_SIGNATURE_FAILURE. The signature
+ *   verification shall use a constant-time algorithm (a signature mismatch
+ *   will always take the same time as a successful comparison).
  *
  * Parameters:
  *   [in] session: handle for the session to be used.
@@ -1877,7 +1862,6 @@ OEMCryptoResult OEMCrypto_RefreshKeys(
  *   OEMCrypto_ERROR_INSUFFICIENT_RESOURCES
  *   OEMCrypto_ERROR_UNKNOWN_FAILURE
  *   OEMCrypto_ERROR_BUFFER_TOO_LARGE
- *   OEMCrypto_ERROR_NO_CONTENT_KEY
  *   OEMCrypto_ERROR_SESSION_LOST_STATE
  *   OEMCrypto_ERROR_SYSTEM_INVALIDATED
  *   ODK_STALE_RENEWAL
@@ -3186,8 +3170,8 @@ OEMCryptoResult OEMCrypto_GetOEMPublicCertificate(uint8_t* public_cert,
  *   OEMCrypto_ERROR_SYSTEM_INVALIDATED
  *
  * Buffer Sizes:
- *   OEMCrypto shall support  dataLength sizes of at least 32 bytes for random
- *   number generation.
+ *   OEMCrypto shall support  random_data_length- sizes of at least 32 bytes
+ *   for random number generation.
  *   OEMCrypto shall return OEMCrypto_ERROR_BUFFER_TOO_LARGE if the buffer is
  *   larger than the supported size.
  *
@@ -3784,8 +3768,8 @@ uint32_t OEMCrypto_GetAnalogOutputFlags(void);
  *   should also support a higher frame rate. Platforms may enforce these
  *   values. For example Android will enforce a frame rate via a GTS test.
  *
- *   Note on units: We will use KiB to mean 1024 bytes and MiB to mean 1024 KiB,
- *   as described at https://en.wikipedia.org/wiki/Kibibyte.
+ *   Note on units: We will use KiB to mean 1024 bytes and MiB to mean 1024
+ *   KiB, as described at https://en.wikipedia.org/wiki/Kibibyte.
  *
  *   +--------------------------------+---------+----------+---------+---------+
  *   |Resource Rating Tier            |1 - Low  |2 - Medium|3 - High |4 - Very |
@@ -4301,7 +4285,7 @@ OEMCryptoResult OEMCrypto_CreateNewUsageEntry(OEMCrypto_SESSION session,
  *   returned and the entry is not loaded.
  *
  *   OEMCrypto shall call ODK_ReloadClockValues, as described in "License
- *   Duration and Renweal" to set the session's clock values.
+ *   Duration and Renewal" to set the session's clock values.
  *
  *   If the entry is already loaded into another open session, then this fails
  *   and returns OEMCrypto_ERROR_INVALID_SESSION. If the session already has a