Add config entry to go2rtc (#129436)

* Add config entry to go2rtc

* Address review comments

* Remove config entry if go2rtc is not configured

* Allow importing default_config

* Address review comment

tests/components/go2rtc/test_config_flow.py

@@ -0,0 +1,45 @@
+"""Test the Home Assistant Cloud config flow."""
+
+from unittest.mock import patch
+
+from homeassistant.components.go2rtc.const import DOMAIN
+from homeassistant.core import HomeAssistant
+from homeassistant.data_entry_flow import FlowResultType
+
+from tests.common import MockConfigEntry
+
+
+async def test_config_flow(hass: HomeAssistant) -> None:
+    """Test create cloud entry."""
+
+    with (
+        patch(
+            "homeassistant.components.go2rtc.async_setup", return_value=True
+        ) as mock_setup,
+        patch(
+            "homeassistant.components.go2rtc.async_setup_entry",
+            return_value=True,
+        ) as mock_setup_entry,
+    ):
+        result = await hass.config_entries.flow.async_init(
+            DOMAIN, context={"source": "system"}
+        )
+        assert result["type"] is FlowResultType.CREATE_ENTRY
+        assert result["title"] == "go2rtc"
+        assert result["data"] == {}
+        await hass.async_block_till_done()
+
+    assert len(mock_setup.mock_calls) == 1
+    assert len(mock_setup_entry.mock_calls) == 1
+
+
+async def test_multiple_entries(hass: HomeAssistant) -> None:
+    """Test creating multiple cloud entries."""
+    config_entry = MockConfigEntry(domain=DOMAIN)
+    config_entry.add_to_hass(hass)
+
+    result = await hass.config_entries.flow.async_init(
+        DOMAIN, context={"source": "system"}
+    )
+    assert result["type"] is FlowResultType.ABORT
+    assert result["reason"] == "single_instance_allowed"