Clarify already-booted comment in boot_simulator

Author: iMostfa

apple/internal/templates/apple_simulator.template.py

@@ -472,11 +472,13 @@ def boot_simulator(*, developer_path: str, simctl_path: str, udid: str) -> None:
   try:
     subprocess.run([simctl_path, "boot", udid], check=True)
   except subprocess.CalledProcessError as e:
-    # When reusing a simulator we may hit "Unable to boot device in current
-    # state: Booted", which exits 149. That is the expected no-op here. Mirror
-    # the test runner's simulator_creator.py: treat 149 as success only after
-    # confirming the device really is booted, so a stuck device (e.g. "Shutting
-    # Down", which also exits 149) still fails loudly.
+    # `simctl boot` errors out if the device is already booted, exiting 149
+    # with "Unable to boot device in current state: Booted". Since our goal is
+    # simply for the device to be booted, that case is already satisfied and we
+    # can carry on. But 149 is not unique to "already booted" -- other states
+    # like "Shutting Down" report it too -- so, as simulator_creator.py does, we
+    # only ignore it after confirming via `simctl list` that the device really
+    # is booted. Every other failure propagates.
     already_booted = False
     if e.returncode == 149:
       list_result = subprocess.run(