Part of fix for TEE resource leaks when app crashes

bug: 9672606

Merge of https://widevine-internal-review.googlesource.com/#/c/6531/
from the widevine CDM repository.

Change-Id: I8ed27cbd9944c3459fce251f1261f7656f99e277

libwvdrmengine/mediadrm/src/WVDrmPlugin.cpp

@@ -40,6 +40,11 @@ WVDrmPlugin::~WVDrmPlugin() {
       ALOGE("Received failure when trying to detach WVDrmPlugin as an event"
             "listener.");
     }
+
+    CdmResponseType res = mCDM->CloseSession(iter->first);
+    if (!isCdmResponseTypeSuccess(res)) {
+      ALOGE("Failed to close session while destroying WVDrmPlugin");
+    }
   }
   mCryptoSessions.clear();
 }