Shorten variable names in e2e test-cases.sh (#407)

* Shorten variable names in e2e test-cases.sh

Rename rslb→rs, reqlb→req1, reqlb2→req2, reqlb3→req3, reqlb4→req4,
reqlb_post_restart→req_post_restart, reqlb_after_delete→req_after_delete,
and instlb→inst.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Signed-off-by: Mike Spreitzer <mspreitz@us.ibm.com>

* Rename launcherlb variables in e2e test-cases.sh

launcherlb→launcher1, launcherlb2→launcher2, launcherlb3→launcher3,
launcherlb4→launcher4, launcherlb_after_delete→launcher_after_delete.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Signed-off-by: Mike Spreitzer <mspreitz@us.ibm.com>

* Rename variables in e2e validate.sh to match test-cases.sh

reqlb→req1, launcherlb→launcher1.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Signed-off-by: Mike Spreitzer <mspreitz@us.ibm.com>

Author: MikeSpreitzer