Open session when checking for OTA keybox support.

[ Merge of http://go/wvgerrit/142089 ]
[ Cherry-pick of http://ag/16496425 ]

Qualcomm's implementation of GenerateOTARequest requires an open
session before attempting to generate an OTA keybox request.  When
checking for OTA keybox support, the dynamic layer was not opening
a session, getting a different error than expected.  Coincidentally,
this would trick the dynamic layer to thinking it was supported, but
hides useful error information.

Bug: 210823889
Test: Android manual testing
Change-Id: I60662d2d9d411c0f999b619d6088aabdba55e2c3

libwvdrmengine/cdm/core/src/oemcrypto_adapter_dynamic.cpp

@@ -1234,14 +1234,28 @@ class Adapter {
   bool IsOTAKeyboxSupported() {
     if (!level1_valid_) return false;
     if (!level1_.GenerateOTARequest) return false;
+    if (!level1_.OpenSession || !level1_.CloseSession) return false;
+    OEMCrypto_SESSION session = 0;
+    OEMCryptoResult result = level1_.OpenSession(&session);
+    if (result != OEMCrypto_SUCCESS) {
+      LOGE("Failed to open keybox OTA session: result = %d", result);
+      return false;
+    }
     size_t buffer_size = 500;  // a large buffer.
     std::vector<uint8_t> buffer(buffer_size);
-    OEMCryptoResult result =
-        level1_.GenerateOTARequest(0, buffer.data(), &buffer_size, 0);
+    result =
+        level1_.GenerateOTARequest(session, buffer.data(), &buffer_size, 0);
     if (result == OEMCrypto_ERROR_SHORT_BUFFER) {
       buffer.resize(buffer_size);
-      result = level1_.GenerateOTARequest(0, buffer.data(), &buffer_size, 0);
+      result =
+          level1_.GenerateOTARequest(session, buffer.data(), &buffer_size, 0);
     }
+    if (result != OEMCrypto_SUCCESS &&
+        result != OEMCrypto_ERROR_NOT_IMPLEMENTED) {
+      LOGE("Unexpected OTA error: buffer_size = %zu, result = %d", buffer_size,
+           static_cast<int>(result));
+    }
+    level1_.CloseSession(session);
     return result == OEMCrypto_SUCCESS;
   }