For #8651 - Ensure FenixSnackbar has a proper root for inflating into

FenixSnackbar, as the platform Snackbar can only be inflated in either a
`CoordinatorLayout` or a `FrameLayout`.
Ensure our HistoryFragment's layout uses one of these as it's root.

app/src/main/res/layout/fragment_history.xml

@@ -2,9 +2,11 @@
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
-<LinearLayout
+
+<FrameLayout
     xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
     android:id="@+id/historyLayout"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
-    android:orientation="vertical"/>
+    tools:context="org.mozilla.fenix.library.history.HistoryFragment" />