[ECO-5082] chore: add sandbox for presence

chat-android/src/test/java/com/ably/chat/SandboxTest.kt

@@ -7,6 +7,7 @@ import org.junit.After
 import org.junit.Assert.assertEquals
 import org.junit.Before
 import org.junit.Test
+import org.junit.runners.model.MultipleFailureException.assertEmpty
 import io.ably.lib.types.ClientOptions as PubSubClientOptions
 
 class SandboxTest {
@@ -24,11 +25,23 @@ class SandboxTest {
     }
 
     @Test
-    fun basicIntegrationTest() = runTest {
+    fun `should return empty list of presence members if nobody is entered`() = runTest {
         val chatClient = createSandboxChatClient(sandbox.apiKey)
         val room = chatClient.rooms.get("basketball")
         room.attach()
-        assertEquals(ChannelState.attached, room.messages.channel.state)
+        val members = room.presence.get()
+        assertEquals(0, members.size)
+    }
+
+    @Test
+    fun `should return yourself as presence member after you entered`() = runTest {
+        val chatClient = createSandboxChatClient(sandbox.apiKey)
+        val room = chatClient.rooms.get("basketball")
+        room.attach()
+        room.presence.enter()
+        val members = room.presence.get()
+        assertEquals(1, members.size)
+        assertEquals("sandbox-client", members.first().clientId)
     }
 }