Bug 1689304 - Update theme screen CTA string r=fluent-reviewers,flod

Differential Revision: https://phabricator.services.mozilla.com/D106822

browser/components/newtab/aboutwelcome/content/aboutwelcome.bundle.js

@@ -1148,7 +1148,7 @@ const DEFAULT_WELCOME_CONTENT = {
       },
       primary_button: {
         label: {
-          string_id: "onboarding-multistage-theme-primary-button-label"
+          string_id: "onboarding-multistage-theme-primary-button-label2"
         },
         action: {
           navigate: true

browser/components/newtab/content-src/lib/aboutwelcome-utils.js

@@ -221,7 +221,7 @@ export const DEFAULT_WELCOME_CONTENT = {
         },
         primary_button: {
           label: {
-            string_id: "onboarding-multistage-theme-primary-button-label",
+            string_id: "onboarding-multistage-theme-primary-button-label2",
           },
           action: {
             navigate: true,

browser/locales/en-US/browser/newtab/onboarding.ftl

@@ -61,7 +61,7 @@ onboarding-welcome-steps-indicator =
 # automatically added to the text inside it. "look" should stay inside the span.
 onboarding-multistage-theme-header = Choose a <span data-l10n-name="zap">look</span>
 onboarding-multistage-theme-subtitle = Personalize { -brand-short-name } with a theme.
-onboarding-multistage-theme-primary-button-label = Save Theme
+onboarding-multistage-theme-primary-button-label2 = Done
 onboarding-multistage-theme-secondary-button-label = Not now
 
 # Automatic theme uses operating system color settings