Skip running app pair flicker tests since it's deprecated

Remove app-pair flicker tests from presubmit and mark them with @Ignore
since app-pair is not currently used but kept in codebase for backup.

Fix: 223076688
Fix: 226869067
Fix: 214190843
Fix: 200778092
Fix: 200777653
Test: atest WMShellFlickerTests
Change-Id: I328d87f87bf9c5f01d86474b850d7d3056aa3ed9