[Fuchsia] Avoid outputting emulator stderr to terminal.

Bug: 1096611
Change-Id: I8d7b3b2898fded0a805e8c4da784703c7e448180
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2252685Reviewed-by: Kevin Marshall <kmarshall@chromium.org>
Commit-Queue: Chong Gu <chonggu@google.com>
Cr-Commit-Position: refs/heads/master@{#780066}

build/fuchsia/aemu_target.py

@@ -83,7 +83,6 @@ class AemuTarget(qemu_target.QemuTarget):
   def _SetEnv(self):
     env = os.environ.copy()
     aemu_logging_env = {
-        "ANDROID_EMU_VK_LOG_CALLS": "1",
         "ANDROID_EMU_VK_NO_CLEANUP": "1",
         "ANDROID_EMUGL_LOG_PRINT": "1",
         "ANDROID_EMUGL_VERBOSE": "1",

build/fuchsia/emu_target.py

@@ -61,11 +61,10 @@ class EmuTarget(target.Target):
     temporary_system_log_file = None
     if self._system_log_file:
       stdout = self._system_log_file
-      stderr = subprocess.STDOUT
     else:
       temporary_system_log_file = tempfile.NamedTemporaryFile('w')
       stdout = temporary_system_log_file
-      stderr = sys.stderr
+    stderr = subprocess.STDOUT
     emu_env = self._SetEnv()
     self._emu_process = subprocess.Popen(emu_command,
                                          stdin=open(os.devnull),