This is an automated cherry-pick of #40141

Signed-off-by: joccau zak.zhao@pingcap.com

What problem does this PR solve?

Issue Number: close #40185

Problem Summary:
If the process of running PITR is killed first, and run PITR again and is successfully, but the show config where name = 'gc.ratio-threshold' and type = 'tikv' is -1

What is changed and how it works?

Set 1.1 (the default value) to gc.ratio-threshold if find the old value is negative after PITR.

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No code

Manual test

1. run the command br restore point to restore log into down-cluster(PITR)
2. kill the br command.
3. do the step 1(PITR) again.
4. PITR successfully
5. show config where name = 'gc.ratio-threshold' and type = 'tikv' is 1.1

Side effects

• Performance regression: Consumes more CPU
• Performance regression: Consumes more Memory
• Breaking backward compatibility

Documentation

• Affects user behaviors
• Contains syntax changes
• Contains variable changes
• Contains experimental features
• Changes MySQL compatibility

Release note

Please refer to Release Notes Language Style Guide to write a quality release note.

Set default value(1.1) to 'gc.ratio-threshold' after PITR successfully.