Use GTEST_SKIP for non keybox devices

Bug: 251240681
Merged from https://widevine-internal-review.googlesource.com/179090

Change-Id: I8c539bfbccde7f22fb732951a95715935935858f

libwvdrmengine/oemcrypto/test/oec_device_features.cpp

@@ -153,7 +153,6 @@ void DeviceFeatures::Initialize() {
 std::string DeviceFeatures::RestrictFilter(const std::string& initial_filter) {
   std::string filter = initial_filter;
   // clang-format off
-  if (!uses_keybox)                   FilterOut(&filter, "*KeyboxTest*");
   // TODO(b/197141970): Need to revisit OEMCryptoLoadsCert* tests for
   // provisioning 4. Disabled here temporarily.
   if (!loads_certificate ||