Merge autoland to mozilla-central. a=merge

browser/app/profile/firefox.js

...tent-src/asrouter/schemas/MessagingExperiment.schema.json

...srouter/templates/PBNewtab/NewtabPromoMessage.schema.json

browser/components/newtab/lib/ASRouter.jsm

browser/components/newtab/lib/OnboardingMessageProvider.jsm

browser/components/newtab/test/unit/unit-entry.js

.../privatebrowsing/content/assets/cookie-banners-begone.svg

browser/components/privatebrowsing/test/browser/browser.ini

...ser/browser_privatebrowsing_about_cookie_banners_promo.js

...st/browser/browser_privatebrowsing_about_default_promo.js

browser/locales/en-US/browser/aboutPrivateBrowsing.ftl

dom/base/BodyStream.cpp

dom/base/BodyStream.h

dom/media/webrtc/third_party_build/build_no_op_commits.sh

dom/media/webrtc/third_party_build/prep_repo.sh

toolkit/modules/BrowserUtils.sys.mjs

toolkit/modules/tests/xpcshell/test_BrowserUtils.js

toolkit/themes/shared/pictureinpicture/player.css

widget/cocoa/MOZIconHelper.h

widget/cocoa/MOZIconHelper.mm