For #11631: Move report site issue extension to main menu. (#15884)

* For #11631: Move report site issue extension to main menu.

* For #11631: Update UI test for installing add-on.

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

@@ -14,6 +14,7 @@ import androidx.test.espresso.UiController
 import androidx.test.espresso.ViewAction
 import androidx.test.espresso.action.ViewActions
 import androidx.test.espresso.action.ViewActions.click
+import androidx.test.espresso.action.ViewActions.swipeDown
 import androidx.test.espresso.assertion.ViewAssertions
 import androidx.test.espresso.assertion.ViewAssertions.matches
 import androidx.test.espresso.contrib.RecyclerViewActions
@@ -532,6 +533,6 @@ private fun assertOpenInAppButton() {
 private fun addonsManagerButton() = onView(withText("Add-ons Manager"))
 
 private fun clickAddonsManagerButton() {
-    onView(withText("Add-ons")).click()
-    addonsManagerButton().click()
+    onView(withId(R.id.mozac_browser_menu_menuView)).perform(swipeDown())
+    onView(withText("Add-ons")).check(matches(isCompletelyDisplayed())).click()
 }

app/src/main/java/org/mozilla/fenix/components/toolbar/DefaultToolbarMenu.kt

@@ -18,11 +18,13 @@ import mozilla.components.browser.menu.item.BrowserMenuHighlightableItem
 import mozilla.components.browser.menu.item.BrowserMenuImageSwitch
 import mozilla.components.browser.menu.item.BrowserMenuImageText
 import mozilla.components.browser.menu.item.BrowserMenuItemToolbar
+import mozilla.components.browser.menu.item.WebExtensionPlaceholderMenuItem
 import mozilla.components.browser.session.Session
 import mozilla.components.browser.session.SessionManager
 import mozilla.components.browser.state.selector.findTab
 import mozilla.components.browser.state.store.BrowserStore
 import mozilla.components.concept.storage.BookmarksStorage
+import mozilla.components.feature.webcompat.reporter.WebCompatReporterFeature
 import mozilla.components.support.ktx.android.content.getColorFromAttr
 import org.mozilla.fenix.HomeActivity
 import org.mozilla.fenix.R
@@ -188,6 +190,7 @@ class DefaultToolbarMenu(
             settings,
             if (shouldDeleteDataOnQuit) deleteDataOnQuit else null,
             BrowserMenuDivider(),
+            reportSiteIssuePlaceholder,
             findInPage,
             addToTopSites,
             addToHomescreen.apply { visible = ::canAddToHomescreen },
@@ -283,6 +286,10 @@ class DefaultToolbarMenu(
         onItemTapped.invoke(ToolbarMenu.Item.FindInPage)
     }
 
+    private val reportSiteIssuePlaceholder = WebExtensionPlaceholderMenuItem(
+        id = WebCompatReporterFeature.WEBCOMPAT_REPORTER_EXTENSION_ID
+    )
+
     private val saveToCollection = BrowserMenuImageText(
         label = context.getString(R.string.browser_menu_save_to_collection_2),
         imageResource = R.drawable.ic_tab_collection,