Add "-Wno-tautological-negation-compare"

Silences the compiler warning:

```
external/icu/icu4c/source/test/intltest/transtst.cpp:224:44: error: reference cannot be bound to dereferenced null pointer in well-defined C++ code; comparison may be assumed to always evaluate to true [-Werror,-Wtautological-undefined-compare]
  224 |             !assertTrue("snext()!=NULL", (&id)!=NULL, true)) {
      |                                            ^~   ~~~~
```

Bug: b/301328082
Change-Id: I7bd862723801e90b448c39dbcdd06989d5d73c8a