recipes: Stop passing --target-arch to envsetup now that it's ignored.

build/scripts/slave/recipes/webrtc_android_apk_trybot.expected/Debug_arm.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "[DEPOT_TOOLS]/gclient.py",
       "config",
       "--spec",
       "cache_dir = None\nsolutions = [{'custom_deps': {'src/third_party/WebKit/LayoutTests': None, 'src/third_party/webrtc': 'http://webrtc.googlecode.com/svn/trunk/webrtc@12345', 'src/webkit/data/layout_tests/LayoutTests': None}, 'custom_vars': {'googlecode_url': 'svn://svn-mirror.golo.chromium.org/%s', 'nacl_trunk': 'svn://svn-mirror.golo.chromium.org/native_client/trunk', 'sourceforge_url': 'svn://svn-mirror.golo.chromium.org/%(repo)s', 'webkit_trunk': 'svn://svn-mirror.golo.chromium.org/blink/trunk'}, 'deps_file': 'DEPS', 'managed': True, 'name': 'src', 'url': 'svn://svn-mirror.golo.chromium.org/chrome/trunk/src'}, {'deps_file': 'DEPS', 'managed': True, 'name': 'webrtc-limited', 'url': 'svn://svn-mirror.golo.chromium.org/chrome-internal/trunk/webrtc-limited'}, {'deps_file': 'DEPS', 'managed': True, 'name': 'webrtc.DEPS', 'url': 'svn://svn-mirror.golo.chromium.org/chrome/trunk/deps/third_party/webrtc/webrtc.DEPS'}]\ntarget_os = ['android']"
     ],
@@ skipping 79 matching lines @@
       "--path-filter",
       "webrtc/"
     ],
     "name": "apply_patch"
   },
   {
     "cmd": [
       "[BUILD]/scripts/slave/env_dump.py",
       "--output-json",
       "/path/to/tmp/json",
-      "[SLAVE_BUILD]/src/build/android/envsetup.sh",
-      "--target-arch=arm"
+      "[SLAVE_BUILD]/src/build/android/envsetup.sh"
     ],
     "name": "envsetup",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@json.output@{@@@",
       "@@@STEP_LOG_LINE@json.output@  \"FOO\": \"bar\", @@@",
       "@@@STEP_LOG_LINE@json.output@  \"GYP_DEFINES\": \"my_new_gyp_def=aaa\"@@@",
       "@@@STEP_LOG_LINE@json.output@}@@@",
       "@@@STEP_LOG_END@json.output@@@"
     ]
   },
@@ skipping 239 matching lines @@
     ],
     "env": {
       "FOO": "bar",
       "GYP_CROSSCOMPILE": "1",
       "GYP_DEFINES": "OS=android component=static_library fastbuild=1 gomadir=[BUILD]/goma host_os=linux include_tests=1 target_arch=arm use_goma=1",
       "GYP_GENERATOR_FLAGS": "default_target=android_builder_webrtc"
     },
     "name": "voice_engine_unittests"
   }
 ]