Bug 1845230 - Adds feature flag for felt privacy

app/.experimenter.yaml

@@ -139,6 +139,14 @@ print:
     share-print-enabled:
       type: boolean
       description: "If true, a print button from the share menu is available."
+private-browsing:
+  description: Private Browsing Mode
+  hasExposure: true
+  exposureDescription: ""
+  variables:
+    felt-privacy-enabled:
+      type: boolean
+      description: "if true, enable felt privacy related UI"
 re-engagement-notification:
   description: A feature that shows the re-engagement notification if the user is inactive.
   hasExposure: true

app/nimbus.fml.yaml

@@ -11,6 +11,7 @@ channels:
   - developer
 includes:
   - onboarding.fml.yaml
+  - pbm.fml.yaml
 import:
   - path: ../../android-components/components/service/nimbus/messaging.fml.yaml
     channel: release

app/pbm.fml.yaml

@@ -0,0 +1,19 @@
+---
+features:
+
+  private-browsing:
+    description: Private Browsing Mode
+
+    variables:
+      felt-privacy-enabled:
+        description: if true, enable felt privacy related UI
+        type: Boolean
+        default: false
+
+    defaults:
+      - channel: developer
+        value:
+          felt-privacy-enabled: true
+      - channel: nightly
+        value:
+          felt-privacy-enabled: false

app/src/main/java/org/mozilla/fenix/utils/Settings.kt

@@ -1676,6 +1676,12 @@ class Settings(private val appContext: Context) : PreferencesHolder {
         }
     }
 
+    val feltPrivateBrowsingEnabled: Boolean
+        get() {
+            FxNimbus.features.privateBrowsing.recordExposure()
+            return FxNimbus.features.privateBrowsing.value().feltPrivacyEnabled
+        }
+
     /**
      * Indicates if the review quality check feature is enabled by the user.
      */