Fixed modules screen crashing on load

This commit fixes the issue of adding single-span items in between full-span items whilst using `StaggeredGridLayoutManager` on recycler view.

Adding such items results in:
```
java.lang.ArrayIndexOutOfBoundsException: Array index out of range: 13
	at java.util.Arrays.rangeCheck(Arrays.java:123)
	at java.util.Arrays.fill(Arrays.java:2828)
	at androidx.recyclerview.widget.StaggeredGridLayoutManager$LazySpanLookup.invalidateAfter(StaggeredGridLayoutManager.java:2876)
	at androidx.recyclerview.widget.StaggeredGridLayoutManager.handleUpdate(StaggeredGridLayoutManager.java:1548)
	at androidx.recyclerview.widget.StaggeredGridLayoutManager.onItemsUpdated(StaggeredGridLayoutManager.java:1524)
	at androidx.recyclerview.widget.RecyclerView$6.dispatchUpdate(RecyclerView.java:1021)
	at androidx.recyclerview.widget.RecyclerView$6.onDispatchSecondPass(RecyclerView.java:1032)
	at androidx.recyclerview.widget.AdapterHelper.consumePostponedUpdates(AdapterHelper.java:121)
	at androidx.recyclerview.widget.AdapterHelper.consumeUpdatesInOnePass(AdapterHelper.java:557)
	at androidx.recyclerview.widget.RecyclerView.dispatchLayoutStep2(RecyclerView.java:4128)
	at androidx.recyclerview.widget.RecyclerView.dispatchLayout(RecyclerView.java:3851)
	at androidx.recyclerview.widget.RecyclerView.onLayout(RecyclerView.java:4404)
	...and more
```

Affects versions including and prior to androidx.recyclerview:recyclerview:1.2.0-alpha02 (at the time of this commit) and possibly more after that.

This bug is caused by a single fact and that is - array inside of `LazySpanLookup` is not being invalidated and resized correctly when non-full-span item is being added in between of two full-span items. The invalidation however passes on some (high performance) devices so it doesn't necessarily cause issues for _some_ users; others keep getting the same crash over and over again.

Possible fix for anyone reading this, in the hope of fixing the same error, is to copy-paste the `StaggeredGridLayoutManager` and fix the array length before calling `Arrays.fill()`. There's no fix from user's perspective if you need to keep the UI as-is.
We however don't need the UI as-is, so we're instead opting to use LinearLayoutManager until is the issue resolved.

Continues tracking at https://issuetracker.google.com/issues/37034096

Close #2631

app/src/main/res/layout/fragment_module_md2.xml

@@ -17,6 +17,17 @@
         android:layout_width="match_parent"
         android:layout_height="match_parent">
 
+        <!--
+        The list is reverted to use LinearLayoutManager only. The issue of random crashes lies in
+        the way StaggeredGridLayoutManager invalidates view in LazySpanLookup. Since we're adding
+        items in between full-span items the array is not yet invalidated and consecutively crashes
+        due to index of -end- being out of bounds of the current array.
+
+        If you'd like to use StaggeredGridLayoutManager, do so without adding single span items in
+        between of full-span items.
+        https://issuetracker.google.com/issues/37034096
+        -->
+
         <androidx.recyclerview.widget.RecyclerView
             android:id="@+id/module_list"
             adapter="@{viewModel.adapter}"
@@ -34,8 +45,7 @@
             android:paddingTop="@{viewModel.insets.top + (int) @dimen/internal_action_bar_size + (int) @dimen/l1}"
             android:paddingEnd="0dp"
             android:paddingBottom="@{viewModel.insets.bottom + (int) @dimen/internal_action_bar_size + (int) @dimen/l1}"
-            app:layoutManager="androidx.recyclerview.widget.StaggeredGridLayoutManager"
+            app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
-            app:spanCount="2"
             tools:listitem="@layout/item_module_md2" />
 
         <com.google.android.material.floatingactionbutton.FloatingActionButton