Allow some quiet period before starting TestShard load

[alexvru]

Changelog entry

Allow some quiet period before starting TestShard load

Changelog category

• Not for changelog (changelog entry is not required)

Additional information

This commit allows changeable interval after TestShard bootup before it starts to generate some load.

[github-actions]

⚪ 2024-12-23 14:17:10 UTC Pre-commit check linux-x86_64-release-asan for 9797c3b has started.
⚪ 2024-12-23 14:17:22 UTC Artifacts will be uploaded here
⚪ 2024-12-23 14:20:43 UTC ya make is running...
🟡 2024-12-23 15:57:20 UTC Some tests failed, follow the links below. This fail is not in blocking policy yet

Test history | Ya make output | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
14048	13965	0	25	12	46

🟢 2024-12-23 15:58:45 UTC Build successful.
🟢 2024-12-23 15:59:10 UTC ydbd size 3.6 GiB changed* by +8.4 KiB, which is < 100.0 KiB vs main: OK

ydbd size dash	main: 5ba6c34	merge: 9797c3b	diff	diff %
ydbd size	3 865 485 648 Bytes	3 865 494 216 Bytes	+8.4 KiB	+0.000%
ydbd stripped size	1 350 611 216 Bytes	1 350 613 488 Bytes	+2.2 KiB	+0.000%

^{*please be aware that the difference is based on comparing your commit and the last completed build from the post-commit, check comparation}

[github-actions]

⚪ 2024-12-23 14:17:41 UTC Pre-commit check linux-x86_64-relwithdebinfo for 9797c3b has started.
⚪ 2024-12-23 14:18:12 UTC Artifacts will be uploaded here
⚪ 2024-12-23 14:21:21 UTC ya make is running...
🟡 2024-12-23 15:51:03 UTC Some tests failed, follow the links below. Going to retry failed tests...

Test history | Ya make output | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
31020	28038	0	34	2833	115

⚪ 2024-12-23 15:54:20 UTC ya make is running... (failed tests rerun, try 2)
🟢 2024-12-23 16:06:23 UTC Tests successful.

Test history | Ya make output | Test bloat | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
200 (only retried tests)	90	0	0	0	110

🟢 2024-12-23 16:06:30 UTC Build successful.
🟢 2024-12-23 16:06:49 UTC ydbd size 2.1 GiB changed* by +3.5 KiB, which is < 100.0 KiB vs main: OK

ydbd size dash	main: 5ba6c34	merge: 9797c3b	diff	diff %
ydbd size	2 234 949 960 Bytes	2 234 953 560 Bytes	+3.5 KiB	+0.000%
ydbd stripped size	477 965 584 Bytes	477 966 032 Bytes	+448 Bytes	+0.000%

^{*please be aware that the difference is based on comparing your commit and the last completed build from the post-commit, check comparation}