Revert "Roll bots to Xcode 12 beta 3"

This reverts commit 1fbe4cc4.

Reason for revert: Xcode 12 beta 3 takes more than 25 seconds to start loading content in WKWebView.

Original change's description:
> Roll bots to Xcode 12 beta 3
>
> Bots rolled with the following script:
> git grep -l '12a6163b' | xargs sed -i '' -e 's/12a6163b/12a8169fg/g'
>
> to update:
> infra/config/lib/builders.star
> infra/config/subprojects/chromium/master-only/ci.star
> infra/config/subprojects/chromium/master-only/try.star
> testing/buildbot/mixins.pyl
> testing/buildbot/waterfalls.pyl
>
> then configs were generated with:
> ./infra/config/main.star
> ./testing/buildbot/generate_buildbot_json.py
>
> CIPD packages:
>   infra_internal/ios/xcode/mac  12a8169fg
>   infra_internal/ios/xcode/ios  12a8169fg
>
> Bug: 1108576
> Change-Id: I0edaaf6d945e0f1e061d930d16194f01b17fd851
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2315436
> Reviewed-by: Dirk Pranke <dpranke@google.com>
> Commit-Queue: Mike Dougherty <michaeldo@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#792067}

TBR=dpranke@google.com,michaeldo@chromium.org,lindsayw@chromium.org,gbeaty@chromium.org,kimstephanie@google.com

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 1108576
Ignore-CQ-Freeze: Changes do not affect CQ.
Change-Id: I94996e3092c9a4f4d5961fc497c8c3e1fade0a0a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2327190Reviewed-by: Erik Staab <estaab@chromium.org>
Reviewed-by: Mike Dougherty <michaeldo@chromium.org>
Commit-Queue: Mike Dougherty <michaeldo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#792824}

infra/config/generated/cr-buildbucket.cfg

@@ -10135,11 +10135,11 @@ buckets {
         cipd_version: "refs/heads/master"
         cmd: "recipes"
       }
-      properties: "{\"$build/goma\":{\"rpc_extra_params\":\"?prod\",\"server_host\":\"goma.chromium.org\"},\"$kitchen\":{\"devshell\":true,\"git_auth\":true},\"mastername\":\"chromium.fyi\",\"recipe\":\"chromium\",\"xcode_build_version\":\"12a8169g\"}"
+      properties: "{\"$build/goma\":{\"rpc_extra_params\":\"?prod\",\"server_host\":\"goma.chromium.org\"},\"$kitchen\":{\"devshell\":true,\"git_auth\":true},\"mastername\":\"chromium.fyi\",\"recipe\":\"chromium\",\"xcode_build_version\":\"12a6163b\"}"
       execution_timeout_secs: 36000
       caches {
-        name: "xcode_ios_12a8169g"
-        path: "xcode_ios_12a8169g.app"
+        name: "xcode_ios_12a6163b"
+        path: "xcode_ios_12a6163b.app"
       }
       build_numbers: YES
       service_account: "chromium-ci-builder@chops-service-accounts.iam.gserviceaccount.com"
@@ -24431,7 +24431,7 @@ buckets {
         cipd_version: "refs/heads/master"
         cmd: "recipes"
       }
-      properties: "{\"$build/goma\":{\"rpc_extra_params\":\"?prod\",\"server_host\":\"goma.chromium.org\"},\"$kitchen\":{\"devshell\":true,\"git_auth\":true},\"mastername\":\"tryserver.chromium.mac\",\"recipe\":\"chromium_trybot\",\"xcode_build_version\":\"12a8169g\"}"
+      properties: "{\"$build/goma\":{\"rpc_extra_params\":\"?prod\",\"server_host\":\"goma.chromium.org\"},\"$kitchen\":{\"devshell\":true,\"git_auth\":true},\"mastername\":\"tryserver.chromium.mac\",\"recipe\":\"chromium_trybot\",\"xcode_build_version\":\"12a6163b\"}"
       execution_timeout_secs: 14400
       expiration_secs: 7200
       caches {
@@ -24439,8 +24439,8 @@ buckets {
         path: "win_toolchain"
       }
       caches {
-        name: "xcode_ios_12a8169g"
-        path: "xcode_ios_12a8169g.app"
+        name: "xcode_ios_12a6163b"
+        path: "xcode_ios_12a6163b.app"
       }
       build_numbers: YES
       service_account: "chromium-try-builder@chops-service-accounts.iam.gserviceaccount.com"

infra/config/lib/builders.star

@@ -141,7 +141,7 @@ xcode_cache = struct(
    x11e503a_xct12b1 = xcode_enum('xcode_ios_11e503a_xct12b1', 'xcode_ios_11e503a_xct12b1.app'),
    x11n700h = xcode_enum('xcode_ios_11n700h', 'xcode_ios_11n700h.app'),
    # xcode12
-   x12a8169g = xcode_enum('xcode_ios_12a8169g', 'xcode_ios_12a8169g.app'),
+   x12a6163b = xcode_enum('xcode_ios_12a6163b', 'xcode_ios_12a6163b.app'),
 )
 
 

infra/config/subprojects/chromium/master-only/ci.star

@@ -1870,11 +1870,11 @@ ci.fyi_ios_builder(
         category = 'iOS|iOS14',
         short_name = 'sdk14',
     ),
-    caches = [xcode_cache.x12a8169g],
+    caches = [xcode_cache.x12a6163b],
     executable = 'recipe:chromium',
     os = os.MAC_10_15,
     properties = {
-        'xcode_build_version': '12a8169g'
+        'xcode_build_version': '12a6163b'
     }
 )
 

infra/config/subprojects/chromium/master-only/try.star

@@ -658,10 +658,10 @@ try_.chromium_mac_ios_builder(
 try_.chromium_mac_ios_builder(
     name = 'ios14-sdk-simulator',
     executable = 'recipe:chromium_trybot',
-    caches = [xcode_cache.x12a8169g],
+    caches = [xcode_cache.x12a6163b],
     os = os.MAC_10_15,
     properties = {
-        'xcode_build_version': '12a8169g'
+        'xcode_build_version': '12a6163b'
     }
 )
 

testing/buildbot/mixins.pyl

@@ -961,17 +961,17 @@
     },
   },
   # xcode 12
-  'xcode_12a8169g': {
+  'xcode_12a6163b': {
     '$mixin_append': {
       'args': [
         '--xcode-build-version',
-        '12a8169g'
+        '12a6163b'
       ],
     },
     'swarming': {
       'named_caches': [
         {
-          'name': 'xcode_ios_12a8169g',
+          'name': 'xcode_ios_12a6163b',
           'path': 'Xcode.app',
         },
       ],

testing/buildbot/waterfalls.pyl

@@ -2132,7 +2132,7 @@
           'mac_10.15',
           'mac_toolchain',
           'out_dir_arg',
-          'xcode_12a8169g',
+          'xcode_12a6163b',
         ],
         'test_suites': {
           'isolated_scripts': 'ios14_beta_simulator_tests'
@@ -2149,7 +2149,7 @@
           'mac_10.15',
           'mac_toolchain',
           'out_dir_arg',
-          'xcode_12a8169g',
+          'xcode_12a6163b',
         ],
         'test_suites': {
           'isolated_scripts': 'ios14_sdk_simulator_tests'