Bug 1635664 - Don't capture the output from sdkmanager in ensure_android_packages. r=rstewart

We always print the output when there is no error. In case of error, we
stick the output in the thrown exception, but nothing actually prints
that out. It's simpler to just let the subprocess print its own output
instead of capturing it, so that important error messages are not hidden
in the case of failure.

Differential Revision: https://phabricator.services.mozilla.com/D74004

python/mozboot/mozboot/android.py

@@ -278,24 +278,21 @@ def ensure_android_packages(sdkmanager_tool, packages=None, no_interactive=False
         subprocess.check_call(args)
         return
 
+    # Flush outputs before running sdkmanager.
+    sys.stdout.flush()
+    sys.stderr.flush()
     # Emulate yes.  For a discussion of passing input to check_output,
     # see https://stackoverflow.com/q/10103551.
     yes = '\n'.join(['y']*100).encode("UTF-8")
-    proc = subprocess.Popen(args,
-                            stdout=subprocess.PIPE,
-                            stderr=subprocess.STDOUT,
-                            stdin=subprocess.PIPE)
-    output, unused_err = proc.communicate(yes)
+    proc = subprocess.Popen(args, stdin=subprocess.PIPE)
+    proc.communicate(yes)
 
     retcode = proc.poll()
     if retcode:
         cmd = args[0]
         e = subprocess.CalledProcessError(retcode, cmd)
-        e.output = output
         raise e
 
-    print(output)
-
 
 def suggest_mozconfig(os_name, artifact_mode=False):
     moz_state_dir, sdk_path, ndk_path = get_paths(os_name)