[KeyboardEsc] Prevent back navigation on Escape for tabs

Now that Escape key presses act as Back buttons by default, we will
navigate back in tab history with each Escape key press, which is not
the desired behavior. The ToolbarManager can simply override the new
invokeBackActionOnEscape method from BackPressHandler and prevent this
behavior change by absorbing the handleEscPress call.

AX-Relnotes: N/A
Bug: 398061359
Change-Id: Id9f7966a32c922e957fac4ef9942df4292c82954
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6492103
Commit-Queue: Mark Schillaci <mschillaci@google.com>
Reviewed-by: Theresa Sullivan <twellington@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1457224}