Add Cirrus macOS as a runner that supports building for Android but not testing (#2514)

* Add Cirrus macOS as a runner that supports building for Android but not testing

* Try to trigger Cirrus by changing .cirrus.yml

.cirrus.yml

@@ -46,8 +46,8 @@ linux_aarch64_task:
   <<: *RUN_TESTS
 
 windows_x86_task:
-  # The task takes ~55 minutes while the timeout happens
-  # after 60 minutes by default, let's allow some wiggle room.
+  # The task takes ~55 minutes while the timeout happens after 60 minutes by default,
+  # let's allow some wiggle room.
   timeout_in: 120m
   windows_container:
     image: cirrusci/windowsservercore:visualstudio2022

test/test_android.py

@@ -28,12 +28,10 @@ if (platform.system(), platform.machine()) not in [
     )
 
 # Detect CI services which have the Android SDK pre-installed.
-ci_supports_build = any(
-    key in os.environ
-    for key in [
-        "GITHUB_ACTIONS",
-        "TF_BUILD",  # Azure Pipelines
-    ]
+ci_supports_build = (
+    ("CIRRUS_CI" in os.environ and platform.system() == "Darwin")
+    or "GITHUB_ACTIONS" in os.environ
+    or "TF_BUILD" in os.environ  # Azure Pipelines
 )
 
 if "ANDROID_HOME" not in os.environ: