Fix issues identified by clang-tidy

- Replace assert with odk_static_assert for checks that can be handled
  at compile time.
- Use explicit bool conversion with memcmp.

Merged from https://widevine-internal-review.googlesource.com/170414

PiperOrigin-RevId: 524277743
Change-Id: I8b32e886e780e80406afceea562be2033d75d340

libwvdrmengine/oemcrypto/odk/src/odk_message.c

@@ -8,20 +8,13 @@
 #include <stdio.h>
 #include <string.h>
 
+#include "odk_assert.h"
 #include "odk_message_priv.h"
 
-/*
- * C11 defines static_assert in assert.h. If it is available, force a compile
- * time error if the abstract ODK_Message struct size does not match its
- * implementation. If static_assert is not available, the runtime assert in
- * InitMessage will catch the mismatch at the time a message is initialized.
- */
-#ifdef static_assert
-static_assert(
+odk_static_assert(
     sizeof(ODK_Message) >= sizeof(ODK_Message_Impl),
     "sizeof(ODK_Message) is too small. You can increase "
     "SIZE_OF_ODK_MESSAGE_IMPL in odk_message.h to make it large enough.");
-#endif
 
 /*
  * Create a message structure that references a separate data buffer. An
@@ -34,7 +27,6 @@ static_assert(
  * unchanged by this function.
  */
 ODK_Message ODK_Message_Create(uint8_t* buffer, size_t capacity) {
-  assert(sizeof(ODK_Message) >= sizeof(ODK_Message_Impl));
   ODK_Message message;
   ODK_Message_Impl* message_impl = (ODK_Message_Impl*)&message;
   message_impl->base = buffer;