add Experimentation helper

app/src/androidTest/java/org/mozilla/fenix/helpers/Experimentation.kt

@@ -0,0 +1,16 @@
+package org.mozilla.fenix.helpers
+
+import org.mozilla.experiments.nimbus.GleanPlumbMessageHelper
+import org.mozilla.fenix.ext.components
+import org.mozilla.fenix.helpers.TestHelper.appContext
+
+object Experimentation {
+    private val nimbus =
+        appContext.components.analytics.experiments
+
+    fun withHelper(block: GleanPlumbMessageHelper.() -> Unit) {
+        val helper = nimbus.createMessageHelper()
+        block(helper)
+    }
+
+}

app/src/androidTest/java/org/mozilla/fenix/ui/NimbusEventTest.kt

@@ -5,9 +5,7 @@ import androidx.test.platform.app.InstrumentationRegistry
 import androidx.test.uiautomator.UiDevice
 import okhttp3.mockwebserver.MockWebServer
 import org.junit.*
-import org.mozilla.fenix.helpers.AndroidAssetDispatcher
+import org.mozilla.fenix.helpers.*
-import org.mozilla.fenix.helpers.HomeActivityIntentTestRule
-import org.mozilla.fenix.helpers.RetryTestRule
 import org.mozilla.fenix.ui.robots.homeScreen
 
 class NimbusEventTest {
@@ -43,9 +41,8 @@ class NimbusEventTest {
     fun homeScreenNimbusEventsTest() {
         homeScreen { }.dismissOnboarding()
 
-        homeScreen {
+        Experimentation.withHelper {
-            verifyHomeScreen()
+            Assert.assertTrue(evalJexl("'app_opened'|eventSum('Days', 28, 0) > 0"))
-            Assert.assertTrue(evaluateAgainstNimbusTargetingHelper("'app_opened'|eventSum('Days', 28, 0) > 0"))
         }
     }
 }

app/src/androidTest/java/org/mozilla/fenix/ui/robots/HomeScreenRobot.kt

@@ -90,7 +90,6 @@ class HomeScreenRobot {
     fun verifyDefaultSearchEngine(searchEngine: String) = verifySearchEngineIcon(searchEngine)
     fun verifyNoTabsOpened() = assertNoTabsOpened()
     fun verifyKeyboardVisible() = assertKeyboardVisibility(isExpectedToBeVisible = true)
-    fun evaluateAgainstNimbusTargetingHelper(jexl: String): Boolean = evaluateAgainstNimbus(jexl)
 
     fun verifyWallpaperImageApplied(isEnabled: Boolean) {
         if (isEnabled) {
@@ -807,14 +806,6 @@ private fun verifySearchEngineIcon(searchEngineName: String) {
     verifySearchEngineIcon(defaultSearchEngine.icon, defaultSearchEngine.name)
 }
 
-private fun getNimbus() =
-    appContext.components.analytics.experiments
-
-private fun evaluateAgainstNimbus(jexl: String): Boolean {
-    val helper = getNimbus().createMessageHelper()
-    return helper.evalJexl(jexl)
-}
-
 // First Run elements
 private fun assertWelcomeHeader() =
     assertTrue(