Revert "infra/config: disable RBE-CAS on ChromeOS builder"

This reverts commit 0b416be.

Reason for revert:
fixed isolate client was rolled in https://crbug.com/1237607#c15

Original change's description:
> infra/config: disable RBE-CAS on ChromeOS builder
>
> Bug: 1237607
> Change-Id: I5ab9e3a5443fb308abff8df06406ca761328fc2b
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3083777
> Auto-Submit: Takuto Ikuta <tikuta@chromium.org>
> Commit-Queue: Ben Pastene <bpastene@chromium.org>
> Reviewed-by: Ben Pastene <bpastene@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#910343}

Bug: 1237607
Change-Id: I6d801d7f38aaf8e845799e33c9682b7a3967d416
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3103245
Auto-Submit: Takuto Ikuta <tikuta@chromium.org>
Commit-Queue: Takuto Ikuta <tikuta@chromium.org>
Commit-Queue: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#912939}

infra/config/generated/cr-buildbucket.cfg

@@ -58054,7 +58054,7 @@ buckets {
       }
       experiments {
         key: "chromium.chromium_tests.use_rbe_cas"
-        value: 0
+        value: 5
       }
       experiments {
         key: "luci.use_realms"
@@ -58155,7 +58155,7 @@ buckets {
       }
       experiments {
         key: "chromium.chromium_tests.use_rbe_cas"
-        value: 0
+        value: 5
       }
       experiments {
         key: "luci.use_realms"
@@ -58255,7 +58255,7 @@ buckets {
       }
       experiments {
         key: "chromium.chromium_tests.use_rbe_cas"
-        value: 0
+        value: 5
       }
       experiments {
         key: "luci.use_realms"
@@ -58356,7 +58356,7 @@ buckets {
       }
       experiments {
         key: "chromium.chromium_tests.use_rbe_cas"
-        value: 0
+        value: 5
       }
       experiments {
         key: "luci.use_realms"
@@ -58456,7 +58456,7 @@ buckets {
       }
       experiments {
         key: "chromium.chromium_tests.use_rbe_cas"
-        value: 0
+        value: 5
       }
       experiments {
         key: "luci.use_realms"
@@ -58557,7 +58557,7 @@ buckets {
       }
       experiments {
         key: "chromium.chromium_tests.use_rbe_cas"
-        value: 0
+        value: 5
       }
       experiments {
         key: "luci.use_realms"
@@ -58657,7 +58657,7 @@ buckets {
       }
       experiments {
         key: "chromium.chromium_tests.use_rbe_cas"
-        value: 0
+        value: 5
       }
       experiments {
         key: "luci.use_realms"
@@ -58758,7 +58758,7 @@ buckets {
       }
       experiments {
         key: "chromium.chromium_tests.use_rbe_cas"
-        value: 0
+        value: 5
       }
       experiments {
         key: "luci.use_realms"
@@ -58859,7 +58859,7 @@ buckets {
       }
       experiments {
         key: "chromium.chromium_tests.use_rbe_cas"
-        value: 0
+        value: 5
       }
       experiments {
         key: "luci.use_realms"
@@ -68216,7 +68216,7 @@ buckets {
       }
       experiments {
         key: "chromium.chromium_tests.use_rbe_cas"
-        value: 0
+        value: 5
       }
       experiments {
         key: "luci.use_realms"
@@ -68316,7 +68316,7 @@ buckets {
       }
       experiments {
         key: "chromium.chromium_tests.use_rbe_cas"
-        value: 0
+        value: 5
       }
       experiments {
         key: "luci.use_realms"
@@ -70134,7 +70134,7 @@ buckets {
       }
       experiments {
         key: "chromium.chromium_tests.use_rbe_cas"
-        value: 0
+        value: 5
       }
       experiments {
         key: "luci.use_realms"
@@ -70234,7 +70234,7 @@ buckets {
       }
       experiments {
         key: "chromium.chromium_tests.use_rbe_cas"
-        value: 0
+        value: 5
       }
       experiments {
         key: "luci.use_realms"
@@ -70335,7 +70335,7 @@ buckets {
       }
       experiments {
         key: "chromium.chromium_tests.use_rbe_cas"
-        value: 0
+        value: 5
       }
       experiments {
         key: "luci.use_realms"
@@ -70436,7 +70436,7 @@ buckets {
       }
       experiments {
         key: "chromium.chromium_tests.use_rbe_cas"
-        value: 0
+        value: 5
       }
       experiments {
         key: "luci.use_realms"
@@ -70541,7 +70541,7 @@ buckets {
       }
       experiments {
         key: "chromium.chromium_tests.use_rbe_cas"
-        value: 0
+        value: 5
       }
       experiments {
         key: "luci.use_realms"
@@ -70649,7 +70649,7 @@ buckets {
       }
       experiments {
         key: "chromium.chromium_tests.use_rbe_cas"
-        value: 0
+        value: 5
       }
       experiments {
         key: "luci.use_realms"
@@ -71654,7 +71654,7 @@ buckets {
       }
       experiments {
         key: "chromium.chromium_tests.use_rbe_cas"
-        value: 0
+        value: 5
       }
       experiments {
         key: "luci.use_realms"

infra/config/lib/try.star

@@ -301,10 +301,6 @@ def chromium_chromiumos_builder(*, name, **kwargs):
         name = name,
         builder_group = "tryserver.chromium.chromiumos",
         goma_backend = builders.goma.backend.RBE_PROD,
-        experiments = {
-            # TODO(crbug.com/1237607): disable rbe cas temporarily.
-            "chromium.chromium_tests.use_rbe_cas": 0,
-        },
         **kwargs
     )