Do not allow clearing Android logs if the emulator is not running

[jchen351]

Description

Do not allow clearing Android logs if the emulator is not running

Motivation and Context

Previously the Clearing Android logs step stuck until the pipeline timeout. If one of the previous steps failed.

[edgchen1]

alternatively, could first check if the emulator has started in the yaml template. then we can keep emulator-specific stuff out of run_adb.py.

e.g., we could check for the existence of $(Build.BinariesDirectory)/emulator.pid in these steps:

onnxruntime/tools/ci_build/github/azure-pipelines/templates/android-dump-logs-from-steps.yml

Lines 8 to 22 in 5e66fcc

	- task: CmdLine@2
	inputs:
	script: |
	python3 tools/python/run_adb.py logcat --clear
	displayName: "Clear Android logs"
	condition: succeededOrFailed()
	- ${{ parameters.steps }}
	- task: CmdLine@2
	inputs:
	script: |
	python3 tools/python/run_adb.py logcat -d
	displayName: "Dump Android logs"
	condition: succeededOrFailed()