example/bzlmod: recommend extra_toolchains flag

In the latest Bazel versions, rules_cc toolchains will take priority
over our own toolchains during automatic resolution.

Recommend users to override the priority by using explicit
--extra_toolchains flag.

Author: sluongng

examples/bzlmod/.bazelrc

@@ -25,7 +25,9 @@ common:remote --remote_executor=grpcs://remote.buildbuddy.io
 # These will take precedence over the default ones.
 #
 # The flags `--extra_execution_platforms` and `--extra_toolchains` are used to override the staticcally
-# registered toolchains and execution platforms.
+# registered toolchains and execution platforms. This is recommended as other Bazel Modules (i.e. rules_cc)
+# may register their cc toolchains earlier and take default priority.
+#
 # For example:
 #
 #   common:remote-linux --extra_execution_platforms=@toolchains_buildbuddy//platforms:linux_x86_64
@@ -49,17 +51,20 @@ common:remote --remote_executor=grpcs://remote.buildbuddy.io
 common:remote-linux --config=remote
 common:remote-linux --platforms=@toolchains_buildbuddy//platforms:linux_x86_64
 common:remote-linux --extra_execution_platforms=@toolchains_buildbuddy//platforms:linux_x86_64
+common:remote-linux --extra_toolchains=@toolchains_buildbuddy//toolchains/cc:ubuntu_gcc_x86_64
 
 common:remote-linux-arm64 --config=remote
 common:remote-linux-arm64 --platforms=@toolchains_buildbuddy//platforms:linux_arm64
 common:remote-linux-arm64 --extra_execution_platforms=@toolchains_buildbuddy//platforms:linux_arm64
+common:remote-linux --extra_toolchains=@toolchains_buildbuddy//toolchains/cc:ubuntu_gcc_arm64
 
 ## Using custom Linux platform
-# 
+#
 # This helps verify that user can extend our platform definitions via inheritence.
 common:custom-linux --config=remote
 common:custom-linux --platforms=//:my_linux_platform
 common:custom-linux --extra_execution_platforms=//:my_linux_platform
+common:remote-linux --extra_toolchains=@toolchains_buildbuddy//toolchains/cc:ubuntu_gcc_x86_64
 
 ## Target Windows platform when build remotely
 #
@@ -70,6 +75,7 @@ common:custom-linux --extra_execution_platforms=//:my_linux_platform
 common:remote-windows --config=remote
 common:remote-windows --platforms=@toolchains_buildbuddy//platforms:windows_x86_64
 common:remote-windows --extra_execution_platforms=@toolchains_buildbuddy//platforms:windows_x86_64
+common:remote-linux --extra_toolchains=@toolchains_buildbuddy//toolchains/cc:windows_msvc_x86_64
 
 
 # Separate file to keep API Key that should have the follow flag