[fenix] For https://github.com/mozilla-mobile/fenix/issues/18175 - Add telemetry for cookies option in custom ETP.

app/metrics.yaml

@@ -1840,6 +1840,32 @@ preferences:
       tags:
         - TrackingProtection
         - Settings
+  etp_custom_cookies_selection:
+    type: string
+    description: |
+      The option user has selected in the "Custom" mode of the
+      Enhanced Tracking Protection settings.
+      Possible values:
+      - total-protection for “Isolate cross-site cookies”
+      - social for “Cross-site and social media trackers”
+      - unvisited for “Cookies from unvisited sites”
+      - third-party for “All third-party cookies..”
+      - all for “All cookies..”
+    send_in_pings:
+      - metrics
+    bugs:
+      - https://github.com/mozilla-mobile/fenix/issues/18175
+    data_reviews:
+      - https://github.com/mozilla-mobile/fenix/pull/26449#issuecomment-1225765591
+    data_sensitivity:
+      - interaction
+    notification_emails:
+      - android-probes@mozilla.com
+    expires: 119
+    metadata:
+      tags:
+        - TrackingProtection
+        - Settings
   bookmarks_suggestion:
     type: boolean
     description: |

app/src/main/java/org/mozilla/fenix/FenixApplication.kt

@@ -758,6 +758,7 @@ open class FenixApplication : LocaleAwareApplication(), Provider {
                     else -> ""
                 }
             )
+            etpCustomCookiesSelection.set(settings.blockCookiesSelectionInCustomTrackingProtection)
 
             val accessibilitySelection = mutableListOf<String>()
 

app/src/test/java/org/mozilla/fenix/FenixApplicationTest.kt

@@ -203,4 +203,17 @@ class FenixApplicationTest {
         assertEquals(contextId, TopSites.contextId.testGetValue()!!.toString())
         assertEquals(contextId, settings.contileContextId)
     }
+
+    @Test
+    fun `GIVEN the current etp mode is custom WHEN tracking the etp metric THEN track also the cookies option`() {
+        val settings: Settings = mockk(relaxed = true) {
+            every { shouldUseTrackingProtection } returns true
+            every { useCustomTrackingProtection } returns true
+            every { blockCookiesSelectionInCustomTrackingProtection } returns "Test"
+        }
+
+        application.setStartupMetrics(browserStore, settings, browsersCache, mozillaProductDetector)
+
+        assertEquals("Test", Preferences.etpCustomCookiesSelection.testGetValue())
+    }
 }