Add clang-tidy support for the CDM

Bug: 256230932
Change-Id: Id3fcf024cd7dcf95218876b81359d6418f5aa067

libwvdrmengine/cdm/metrics/include/metrics_collections.h

@@ -61,7 +61,6 @@
 
 namespace wvcdm {
 namespace metrics {
-namespace {
 // Short name definitions to ease AttributeHandler definitions.
 // Internal namespace to help simplify declarations.
 const int kErrorCodeFieldNumber =
@@ -91,7 +90,6 @@ const int kLicenseTypeFieldNumber =
     ::drm_metrics::Attributes::kLicenseTypeFieldNumber;
 const int kOemCryptoSignatureHashAlgorithmFieldNumber =
     ::drm_metrics::Attributes::kOemCryptoSignatureHashAlgorithmFieldNumber;
-}  // namespace
 
 // The maximum number of completed sessions that can be stored. More than this
 // will cause some metrics to be discarded.