[Bug] fix checkpoint and enable test

[monusingh-1]

Description

Add statement which was responsible for updating follower checkpoint.

Enable test for follower check point.

Issues Resolved

[List any issues this PR will resolve]

Check List

• New functionality includes testing.
  • All tests pass
• New functionality has been documented.
  • New functionality has javadoc added
• Commits are signed per the DCO using --signoff

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[codecov]

Codecov Report

Merging #1110 (529ecfe) into 2.7 (d97859a) will increase coverage by 2.16%.
The diff coverage is 100.00%.

❗ Current head 529ecfe differs from pull request most recent head 729f787. Consider uploading reports for the commit 729f787 to get more accurate results

@@             Coverage Diff              @@
##                2.7    #1110      +/-   ##
============================================
+ Coverage     72.95%   75.11%   +2.16%     
- Complexity     1022     1037      +15     
============================================
  Files           141      141              
  Lines          4769     4770       +1     
  Branches        534      534              
============================================
+ Hits           3479     3583     +104     
+ Misses          961      854     -107     
- Partials        329      333       +4     

Files Changed	Coverage Δ
...search/replication/task/shard/TranslogSequencer.kt	73.84% <100.00%> (+0.40%)	⬆️

... and 11 files with indirect coverage changes