Merge recent doc changes for OEMCrypto

This is a cherry pick of recent changes to OEMCrypto and ODK. Most of
these are part of the document migration to doxygen.

See http://go/wvgerrit/106005 and its parents for code reviews.

Bug: 144715340
Bug: 148232693
Bug: 167580674
Change-Id: I658f99c8117b974faed97322d61fac0f382283af

libwvdrmengine/oemcrypto/test/fuzz_tests/sample_test.cc

@@ -0,0 +1,10 @@
+#include <stddef.h>
+#include <stdint.h>
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+  if (size > 0 && data[0] == 'H')
+    if (size > 1 && data[1] == 'I')
+       if (size > 2 && data[2] == '!')
+       __builtin_trap();
+  return 0;
+}