Add new optional fields to OEMCrypto_BuildInformation output

Bug: 273347757

Merged from https://widevine-internal-review.googlesource.com/168937

Change-Id: I0f878cab8456fa277a453d76e4deb4a2a846ede9

libwvdrmengine/oemcrypto/include/OEMCryptoCENC.h

@@ -3350,6 +3350,22 @@ uint32_t OEMCrypto_MinorAPIVersion(void);
  * While not required, the following top level fields are recommended:
  * - "implementer" [string]: Name of company or entity that provides OEMCrypto.
  *   Important if not SOC vendor.
+ * - "git_commit" [string]: Git commit hash of the code repository that
+ *   produced the TA build. Useful for implementers to distinguish the state of
+ *   different TA builds.
+ * - "build_timestamp" [string]: ISO 8601 formatted timestamp of the time the
+ *   TA was compiled, eg "YYYY-MM-DDTHH:MM:SS"
+ *
+ * While not required, another optional top level struct can be added to the
+ * build information string to provide information about liboemcrypto.so:
+ * - "ree" {
+ *     - "liboemcrypto_ver" [string]: liboemcrypto.so version in string format
+ *       eg "2.15.0+tag". Note that this is separate from the "ta_ver" field
+ *       above, since this section is specific to the liboemcrypto.so binary.
+ *     - "git_commit" [string]: git hash of code that compiled liboemcrypto.so
+ *     - "build_timestamp" [string]: ISO 8601 timestamp for when
+ *       liboemcrypto.so was built
+ *   }
  *
  * The JSON string can contain other values, structs, arrays, etc in addition to
  * the above, if desired.