Use new `metalava signature-to-jdiff` sub-command

Also, removes `--no-banner` as it is deprecated and `--format=v2` is
unnecessary.

Bug: 290825755
Test: m current-api-xml
(cherry picked from https://android-review.googlesource.com/q/commit:aab881d8b7ebea74266039275d0f5bf7019e1a5b)
Merged-In: Ib2ff55cf2bfd2128866b2e4f67cf39303135b79b
Change-Id: Ib2ff55cf2bfd2128866b2e4f67cf39303135b79b
Bug: 299428102