Add android-mac build job to taskcluster.

etc/ci/buildbot_steps.yml

@@ -124,16 +124,6 @@ linux-nightly:
   - rm -rf ./python/_virtualenv
   - ./etc/ci/clean_build_artifacts.sh
 
-android-mac:
- commands:
-  - ./mach clean-nightlies --keep 3 --force
-  - ./mach clean-cargo-cache --keep 3 --force
-  - ./mach bootstrap-android --accept-all-licences --build
-  - ./mach build --android --dev
-  - ./mach package --android --dev
-  - bash ./etc/ci/lockfile_changed.sh
-  - ./etc/ci/clean_build_artifacts.sh
-
 magicleap:
  env:
   MAGICLEAP_SDK: /Users/servo/magicleap/v0.17.0
@@ -225,6 +215,7 @@ arm64:
 linux-dev: []
 mac-dev-unit: []
 windows-msvc-dev: []
+android-mac: []
 android: []
 android-x86: []
 mac-rel-wpt1: []