libwvhidl: implement API to get plugin logs

Bug: 162255728
Test: VtsHalDrmV1_4TargetTest
Change-Id: I333cb1ee2f25ae718e7f544f4a5f7ee50668041a

libwvdrmengine/mediacrypto/include_hidl/WVCryptoPlugin.h

@@ -61,6 +61,9 @@ struct WVCryptoPlugin : public ::drm::V1_4::ICryptoPlugin {
       const DestinationBuffer& destination,
       decrypt_1_2_cb _hidl_cb) override;
 
+  Return<void> getLogMessages(
+      getLogMessages_cb _hidl_cb) override;
+
  private:
   WVDRM_DISALLOW_COPY_AND_ASSIGN_AND_NEW(WVCryptoPlugin);