webrtc-sys: android.cpp uses __sF which was removed in NDK 28+

[fraschm1998]

Problem

webrtc-sys/src/android.cpp lines 33-37 reference __sF, a libc symbol that was removed in Android NDK 28:

#undef stdout
FILE *stdout = &__sF[1];

#undef stderr
FILE *stderr = &__sF[2];

This causes a compilation error when building with NDK 28 or 29:

src/android.cpp:34:17: error: use of undeclared identifier '__sF'
   34 | FILE *stdout = &__sF[1];

Fix

Replace with POSIX-standard fdopen:

#include <unistd.h>
#undef stdout
FILE *stdout = fdopen(STDOUT_FILENO, "w");
#undef stderr
FILE *stderr = fdopen(STDERR_FILENO, "w");

This is compatible with all NDK versions.

Environment

• webrtc-sys 0.3.27
• NDK 28.0.12916984 and 29.0.14206865
• Target: aarch64-linux-android