Use a template for Android test spec (#7091)

* Use a template for Android test spec

* Minor workflow tweak

* Fix wrong workflow format

* Add checkout step to get the spec

* Use linux_job_v2.yml

* Fix test_llama invocation after https://github.com/pytorch/executorch/pull/6870

* Use curl instead

* Format

* Copy file silently

* Route adb push output to /dev/null

* No need to use linux_job_v2 for now

* Clean up upload-android-test-specs workflow