Fix UiAutomation#executeAndWaitForEvent for nested calls

There could be more than one nested caller completing
their work in executeAndWaitForEvent, UiAutomation should
capture accessibility events until when there is at least
one such caller/client is active.

Also, cleaning recycle method as its a no op now.

Fix: 390024533
Test: atest LocationAccuracyTest
Test: atest EnhanchedConfirmationManagerTest
Test: atest android.permissionui.cts.MediaPermissionTest#testWhenRESIsGrantedFromGrantDialogThenShouldGrantAllPermissions
Flag: EXEMPT bug fix
Change-Id: Ief99c1f58f43cc87fd8dec4f9750f32c970eb3d9