Add yet more Firefox needle variants

I don't know why the ones I *just created* don't always match,
but they don't. Let's just have a bunch of needles and in a few
weeks I'll look and see if any are never matching, and get rid
of them.

Signed-off-by: Adam Williamson <awilliam@redhat.com>

needles/firefox/addon_install-alt-20190319.json

@@ -0,0 +1,22 @@
+{
+  "area": [
+    {
+      "width": 35,
+      "type": "match",
+      "ypos": 108,
+      "xpos": 241,
+      "height": 35
+    },
+    {
+      "height": 13,
+      "xpos": 542,
+      "type": "match",
+      "ypos": 278,
+      "width": 26
+    }
+  ],
+  "properties": [],
+  "tags": [
+    "firefox_addon_install"
+  ]
+}

needles/firefox/firefox_close_tabs-alt-20190319.json

@@ -0,0 +1,15 @@
+{
+  "area": [
+    {
+      "height": 13,
+      "xpos": 668,
+      "ypos": 419,
+      "type": "match",
+      "width": 68
+    }
+  ],
+  "properties": [],
+  "tags": [
+    "firefox_close_tabs"
+  ]
+}