Added metrics for production readiness.

[ Merge of http://go/wvgerrit/151749 ]

Extended CryptoSession for recording the result of
OEMCrypto_ProductionReady().

Only OEMCrypto_SUCCESS is considered "production ready".  With the
exception of OEMCrypto_ERROR_NOT_IMPLEMENTED, any other result is
vendor-specific and indicates not being production ready.

Bug: 231655151
Test: metrics_collections_unittest
Change-Id: Ia0e5603d7ee1290238cce63d0194ae1aced424c1

libwvdrmengine/cdm/metrics/include/metrics_collections.h

@@ -298,6 +298,7 @@ class CryptoMetrics {
   EventMetric<kOemCryptoResultFieldNumber, OEMCryptoResult>
       oemcrypto_install_oem_private_key_;
   ValueMetric<int> oemcrypto_watermarking_support_;
+  ValueMetric<int> oemcrypto_production_readiness_;
 };  // class CryptoMetrics
 
 // This class contains session-scoped metrics. All properties and