Save import items count after getting it from schema mapping

[UgnineSirdis]

Changelog entry

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Changelog category

• Not for changelog (changelog entry is not required)

Description for reviewers

We need to save save items count setting after we read SchemaMapping, because it changes items count

[github-actions]

🟢 2025-06-19 21:49:47 UTC The validation of the Pull Request description is successful.

[github-actions]

⚪ 2025-06-21 15:43:36 UTC Pre-commit check linux-x86_64-relwithdebinfo for 608ff2f has started.
⚪ 2025-06-21 15:43:48 UTC Artifacts will be uploaded here
⚪ 2025-06-21 15:47:00 UTC ya make is running...
🟡 2025-06-21 16:47:43 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?
29131	27752	0	2	1346	31

⚪ 2025-06-21 16:50:13 UTC ya make is running... (failed tests rerun, try 2)
🟢 2025-06-21 17:00:35 UTC Tests successful.

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

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
516 (only retried tests)	486	0	0	0	30

🟢 2025-06-21 17:00:44 UTC Build successful.
🟢 2025-06-21 17:01:02 UTC ydbd size 2.2 GiB changed* by +224 Bytes, which is < 100.0 KiB vs main: OK

ydbd size dash	main: 6065f1e	merge: 608ff2f	diff	diff %
ydbd size	2 376 303 640 Bytes	2 376 303 864 Bytes	+224 Bytes	+0.000%
ydbd stripped size	497 974 856 Bytes	497 974 920 Bytes	+64 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}

[github-actions]

⚪ 2025-06-19 21:52:53 UTC Pre-commit check linux-x86_64-release-asan for 608ff2f has started.
⚪ 2025-06-19 21:52:57 UTC Artifacts will be uploaded here
⚪ 2025-06-19 21:56:16 UTC ya make is running...
🟡 2025-06-19 23:41:37 UTC Some tests failed, follow the links below. This fail is not in blocking policy yet Going to retry failed tests...

Test history | Ya make output | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
13891	13461	0	205	199	26

⚪ 2025-06-19 23:42:51 UTC ya make is running... (failed tests rerun, try 2)
🟡 2025-06-20 00:18:53 UTC Some tests failed, follow the links below. This fail is not in blocking policy yet Going to retry failed tests...

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

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
1881 (only retried tests)	1612	0	69	174	26

⚪ 2025-06-20 00:19:12 UTC ya make is running... (failed tests rerun, try 3)
🟡 2025-06-20 00:55:06 UTC Some tests failed, follow the links below. This fail is not in blocking policy yet

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

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
1653 (only retried tests)	1395	0	55	178	25

🟢 2025-06-20 00:55:23 UTC Build successful.
🟢 2025-06-20 00:56:00 UTC ydbd size 3.9 GiB changed* by +336 Bytes, which is < 100.0 KiB vs main: OK

ydbd size dash	main: 6065f1e	merge: 608ff2f	diff	diff %
ydbd size	4 180 038 752 Bytes	4 180 039 088 Bytes	+336 Bytes	+0.000%
ydbd stripped size	1 449 114 744 Bytes	1 449 114 872 Bytes	+128 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}

[CyberROFL]

Можно ли воспроизвести проблему в тесте?