fix(android): give cluster markers a TalkBack label

package/android/src/main/java/com/margelo/nitro/nitromaps/ClusterElement+AccessibilityLabel.kt

@@ -0,0 +1,6 @@
+package com.margelo.nitro.nitromaps
+
+import android.content.res.Resources
+
+internal fun ClusterElement.Cluster.accessibilityLabel(resources: Resources): String =
+  resources.getQuantityString(R.plurals.better_maps_cluster_description, count, count)

package/android/src/main/java/com/margelo/nitro/nitromaps/MapOverlayController.kt

@@ -316,6 +316,7 @@ internal class MapOverlayController(
               .position(element.position)
               .icon(iconFactory.icon(element.count))
               .anchor(0.5f, 0.5f)
+              .title(element.accessibilityLabel(context.resources))
           if (shouldAnimate) {
             options.alpha(0f)
           }
@@ -356,6 +357,7 @@ internal class MapOverlayController(
           marker.alpha = 1f
           marker.position = element.position
           marker.setIcon(iconFactory.icon(element.count))
+          marker.title = element.accessibilityLabel(context.resources)
           clusterByKey[key] = element
         }
       }

package/android/src/main/res/values/strings.xml

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+  <plurals name="better_maps_cluster_description">
+    <item quantity="one">%d marker in this cluster</item>
+    <item quantity="other">%d markers in this cluster</item>
+  </plurals>
+</resources>