onnxruntime

Migrate Android Java E2E tests from App Center to Browserstack (#22117)

### Description
- removed installing AppCenter + pipeline step that runs AppCenter
Espresso tests
- added script for running AppCenter tests

### Motivation and Context
App Center is getting deprecated in the next year + we have upcoming
Android work that depends on working E2E testing.

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Co-authored-by: Edward Chen <18449977+edgchen1@users.noreply.github.com>