Fix the UI tests. (#4085)

* Compile errors 😬

* Update server selection snapshots.

The default footer string has changed.

* Remove the TemplateScreen UI tests.

We use preview tests for snapshots now, UI tests are for flow coordinators.

* Add the same looping on the OIDC UI test (but disable the test in the end).

* Run UI tests separately for iPhone and iPad.

GitHub runners don't seem to have enough memory to handle 2 simulators at once.

fastlane/Fastfile

@@ -105,17 +105,28 @@ lane :unit_tests do |options|
 end
 
 lane :ui_tests do |options|
-  create_simulator_if_necessary(
-    name: "iPhone-18.4",
-    type: "com.apple.CoreSimulator.SimDeviceType.iPhone-16",
-    runtime: "com.apple.CoreSimulator.SimRuntime.iOS-18-4"
-  )
+  # We used to run these simultaneously on iPhone and iPad but it is *really* slow on GitHub runners.
+  # Presumably because launching 2 simulators uses more memory than the runner has available.
   
-  create_simulator_if_necessary(
-    name: "iPad-18.4",
-    type: "com.apple.CoreSimulator.SimDeviceType.iPad-10th-generation",
-    runtime: "com.apple.CoreSimulator.SimRuntime.iOS-18-4"
-  )
+  if options[:device] == "iPhone"
+    device = "iPhone-18.4"
+    
+    create_simulator_if_necessary(
+      name: "iPhone-18.4",
+      type: "com.apple.CoreSimulator.SimDeviceType.iPhone-16",
+      runtime: "com.apple.CoreSimulator.SimRuntime.iOS-18-4"
+    )
+  elsif options[:device] == "iPad"
+    device = "iPad-18.4"
+    
+    create_simulator_if_necessary(
+      name: "iPad-18.4",
+      type: "com.apple.CoreSimulator.SimDeviceType.iPad-10th-generation",
+      runtime: "com.apple.CoreSimulator.SimRuntime.iOS-18-4"
+    )
+  else
+    UI.user_error!("Please supply a device argument as device:iPhone or device:iPad")
+  end
 
   if options[:test_name]
     test_to_run = ["UITests/#{options[:test_name]}"]
@@ -124,12 +135,12 @@ lane :ui_tests do |options|
   end
 
   reset_simulator = ENV.key?('CI')
-
+  
   run_tests(
     scheme: "UITests",
-    devices: ["iPhone-18.4", "iPad-18.4"],
+    device: device,
     ensure_devices_found: true,
-    prelaunch_simulator: true,
+    prelaunch_simulator: false,
     result_bundle: true,
     only_testing: test_to_run,
     number_of_retries: 3,