Bug 1833093 - Add a Nimbus experiment for pdf.js

app/.experimenter.yaml

@@ -109,6 +109,17 @@ onboarding:
     order:
       type: json
       description: Determines the order of the onboarding page panels
+pdfjs:
+  description: PDF.js features
+  hasExposure: true
+  exposureDescription: ""
+  variables:
+    download-button:
+      type: boolean
+      description: Download button
+    open-in-app-button:
+      type: boolean
+      description: Open in app button
 pre-permission-notification-prompt:
   description: A feature that shows the pre-permission notification prompt.
   hasExposure: true

app/nimbus.fml.yaml

@@ -131,6 +131,15 @@ import:
                 max-display-count: 1
             notification-config:
               refresh-interval: 120 # minutes (2 hours)
+  - path: ../../android-components/components/browser/engine-gecko/geckoview.fml.yaml
+    channel: release
+    features:
+      pdfjs:
+        - channel: developer
+          value: {
+          download-button: true,
+          open-in-app-button: true
+        }
 
 features:
   homescreen: