Fix for b/4132041 Widevine DRM plugin getConstraints not returning error

Change-Id: I07f02aabb4b68287eb7978abb5d106c86f2790b6

proprietary/drmwvmplugin/src/WVMDrmPlugin.cpp

@@ -331,12 +331,16 @@ DrmConstraints* WVMDrmPlugin::onGetConstraints(int uniqueId, const String8* path
     bool denyHD;
 
     std::string assetPath(path->string());
-    if (!mDrmPluginImpl->GetConstraints(assetPath, &timeSincePlayback, &timeRemaining, 
+    bool isValid = mDrmPluginImpl->GetConstraints(assetPath, &timeSincePlayback, &timeRemaining,
                                                   &licenseDuration, lastError, allowOffline,
-                                        allowStreaming, denyHD))
-        return NULL;
+                                                  allowStreaming, denyHD);
 
     DrmConstraints* drmConstraints =  new DrmConstraints();
+
+    String8 key = String8("WVLastErrorKey");
+    drmConstraints->put(&key, lastError.c_str());
+
+    if (isValid) {
         char charValue[16]; // max uint32 = 0xffffffff + terminating char
 
         memset(charValue, 0, 16);
@@ -351,16 +355,15 @@ DrmConstraints* WVMDrmPlugin::onGetConstraints(int uniqueId, const String8* path
         sprintf(charValue, "%lu", (unsigned long)licenseDuration);
         drmConstraints->put(&(DrmConstraints::LICENSE_AVAILABLE_TIME), charValue);
 
-    String8 key = String8("WVLicenseTypeKey");
+        key = String8("WVLicenseTypeKey");
         sprintf(charValue, "%u", (allowStreaming ? 1 : 0) | (allowOffline ? 2 : 0));
         drmConstraints->put(&key, charValue);
 
         key = String8("WVLicensedResolutionKey");
         sprintf(charValue, "%u", (denyHD ? 1 : 2));
         drmConstraints->put(&key, charValue);
+    }
 
-    key = String8("WVLastErrorKey");
-    drmConstraints->put(&key, lastError.c_str());
     return drmConstraints;
 }