Bug 1881016 - Added experimental onboarding strings for Nimbus (#5936)

Co-authored-by: t-p-white <towhite@mozilla.com>
Co-authored-by: t-p-white <1833156+t-p-white@users.noreply.github.com>

app/src/main/res/values/strings.xml

@@ -321,11 +321,15 @@
     <!-- Title for set firefox as default browser screen used by Nimbus experiments.
         Note: The word "Firefox" should NOT be translated -->
     <string name="juno_onboarding_default_browser_title_nimbus_3" tools:ignore="UnusedResources">Find out why millions love Firefox</string>
+    <!-- Title for set firefox as default browser screen used by Nimbus experiments. -->
+    <string name="juno_onboarding_default_browser_title_nimbus_4" tools:ignore="UnusedResources">Safe browsing with more choices</string>
     <!-- Description for set firefox as default browser screen used by Nimbus experiments. -->
     <string name="juno_onboarding_default_browser_description_nimbus_3">Our non-profit backed browser helps stop companies from secretly following you around the web.</string>
     <!-- Description for set firefox as default browser screen used by Nimbus experiments. -->
     <string name="juno_onboarding_default_browser_description_nimbus_4" tools:ignore="UnusedResources">More than 100 million people protect their privacy by choosing a browser that’s backed by a nonprofit.</string>
     <!-- Description for set firefox as default browser screen used by Nimbus experiments. -->
+    <string name="juno_onboarding_default_browser_description_nimbus_5" tools:ignore="UnusedResources">Known trackers? Blocked automatically. Extensions? Try all 700. PDFs? Our built-in reader makes them easy to manage.</string>
+    <!-- Description for set firefox as default browser screen used by Nimbus experiments. -->
     <string name="juno_onboarding_default_browser_description_nimbus_2" moz:RemovedIn="124" tools:ignore="UnusedResources">Our non-profit backed browser helps stop companies from secretly following you around the web.\n\nLearn more in our privacy notice.</string>
     <!-- Text for the link to the privacy notice webpage for set as firefox default browser screen.
     This is part of the string with the key "juno_onboarding_default_browser_description". -->