[roll] Roll fuchsia [rbe][bazel] Add bazel to rbe_modes.

For now, still leave it disabled by default.

Added some descriptions to the rbe mode definitions.

Original-Bug: 344673187
Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1064675
Original-Revision: a0a3196c0ee8a736c38335d81d11d18965d8fa66
GitOrigin-RevId: 52e177f1cf83b2bd8924da1fb1a02ebba87c395f
Change-Id: I2ef9eb759b280c7fd43c9de89e5a1b917a004c6e
diff --git a/stem b/stem
index 62b5920..bbe5f92 100644
--- a/stem
+++ b/stem
@@ -11,7 +11,7 @@
              githooks="integration/git-hooks"
              remote="https://fuchsia.googlesource.com/fuchsia"
              gerrithost="https://fuchsia-review.googlesource.com"
-             revision="e8be579f29e3e6097e69d5988a605bcb534fb83a"/>
+             revision="a0a3196c0ee8a736c38335d81d11d18965d8fa66"/>
   </projects>
   <hooks>
     <hook name="install-environment"