[fenix] For https://github.com/mozilla-mobile/fenix/issues/8422: Add spacing between migration items

app/src/main/java/org/mozilla/fenix/migration/MigrationProgressActivity.kt

@@ -5,10 +5,12 @@
 package org.mozilla.fenix.migration
 
 import android.content.Intent
+import android.graphics.Rect
 import android.os.Bundle
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
+import androidx.annotation.DimenRes
 import androidx.core.content.ContextCompat
 import androidx.recyclerview.widget.DiffUtil
 import androidx.recyclerview.widget.LinearLayoutManager
@@ -52,6 +54,8 @@ class MigrationProgressActivity : AbstractMigrationProgressActivity() {
         }
 
         migration_status_list.apply {
+            val margin = resources.getDimensionPixelSize(R.dimen.migration_margin)
+            addItemDecoration(MigrationStatusItemDecoration(margin))
             layoutManager = LinearLayoutManager(this@MigrationProgressActivity)
             adapter = statusAdapter
         }
@@ -158,3 +162,23 @@ internal class MigrationStatusAdapter :
                 oldItem.status == newItem.status
     }
 }
+
+internal class MigrationStatusItemDecoration(
+    @DimenRes private val spacing: Int
+) : RecyclerView.ItemDecoration() {
+
+    override fun getItemOffsets(
+        outRect: Rect,
+        view: View,
+        parent: RecyclerView,
+        state: RecyclerView.State
+    ) {
+        val position = parent.getChildViewHolder(view).adapterPosition
+        val itemCount = state.itemCount
+
+        outRect.left = spacing
+        outRect.right = spacing
+        outRect.top = spacing
+        outRect.bottom = if (position == itemCount - 1) spacing else 0
+    }
+}