rust_binderfs: add transaction_report feature entry

rust_binderfs is missing the equivalent of commit f37b55ded8ed ("binder:
add transaction_report feature entry"), which adds "transaction_report"
to the binderfs feature list. This helps userspace determine if the
BINDER_CMD_REPORT from the generic netlink API is supported.

Cc: stable <stable@kernel.org>
Fixes: f14e0c8183bc ("rust_binder: report netlink transactions")
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Link: https://patch.msgid.link/20260916120833.593407-1-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>