Clean up after renaming the be channel to main. (#115)

* Clean up after renaming the be channel to main.

Bug: b/299435467

* recompile the javascript code (#116)

recompile the javascript code; normalize sig generation

* Update tool/sig.dart

Co-authored-by: Jacob MacDonald <jakemac@google.com>

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Co-authored-by: Devon Carew <devoncarew@google.com>
Co-authored-by: Jacob MacDonald <jakemac@google.com>

Author: 3 people