Remove __DATE__ and __TIME__ from tracing

Including __DATE__ and __TIME__ in the binary means that every build of
this library is different, even if the sources are identical. It also
means that every OTA needs to patch this library. Remove __DATE__ and
__TIME__ from the trace build info, just record whether it's a debug or
release build.

Bug: 24204119
Change-Id: I0dfc1479f096197007db1920b89aeb61ea537168
(cherry picked from commit e3422c11696e715e66b1669230410f098bf4c038)

src/system_wrappers/source/trace_posix.cc

@@ -33,8 +33,12 @@
 #endif
 #define BUILDTIME __TIME__
 #define BUILDDATE __DATE__
+#ifdef __ANDROID__
+#define BUILDINFO BUILDMODE
+#else
 // example: "Oct 10 2002 12:05:30 r"
 #define BUILDINFO BUILDDATE " " BUILDTIME " " BUILDMODE
+#endif
 
 namespace webrtc {
 TracePosix::TracePosix()