Declare class for drmFactory, crypto/drmPlugins

[ Merged from http://go/wvgerrit/152493 ]

Replace struct with class for WVDrmFactory, WVCryptoPlugin
and WVDrmPlugin.

Also fix build_all_unit_tests.sh, hidl_metrics_adapter_unittest
has been renamed to hal_metrics_adapter_unittest.

Test: unit tests
Test: Google TV and Netflix
Test: atest GtsMediaTestCases

Bug: 216717460
Change-Id: I92b15510267e8f37058845be760a6ec6241bc5d7

libwvdrmengine/aidl_include/WVDrmFactory.h

@@ -19,7 +19,8 @@ namespace hardware {
 namespace drm {
 namespace widevine {
 
-struct WVDrmFactory : public ::aidl::android::hardware::drm::BnDrmFactory {
+class WVDrmFactory : public ::aidl::android::hardware::drm::BnDrmFactory {
+ public:
   WVDrmFactory() {}
   virtual ~WVDrmFactory() {}