don't log shrink metrics on first call

[jeffwashington]

Problem

Shrink metrics always log on first call after creation. This causes noise and bifurcated metrics.

Summary of Changes

Wait to log until it has been 1 second.
Fixes #

[jeffwashington]

this pr:
datapoint: shrink_stats num_slots_shrunk=2990i storage_read_elapsed=0i index_read_elapsed=307621i find_alive_elapsed=10353i create_and_insert_store_elapsed=55275i store_accounts_elapsed=354651i update_index_elapsed=177512i handle_reclaims_elapsed=86620i write_storage_elapsed=2i rewrite_elapsed=693354i drop_storage_entries_elapsed=26i recycle_stores_write_time=225i accounts_removed=4165i bytes_removed=2875392i store_append_accounts=161636i store_find_store=0i store_hash_accounts=0i build_meta_time=168044i read_only_cache=129070i
master:
datapoint: shrink_stats num_slots_shrunk=1i storage_read_elapsed=0i index_read_elapsed=59i find_alive_elapsed=3i create_and_insert_store_elapsed=192i store_accounts_elapsed=100i update_index_elapsed=43i handle_reclaims_elapsed=32i write_storage_elapsed=0i rewrite_elapsed=373i drop_storage_entries_elapsed=0i recycle_stores_write_time=0i accounts_removed=1i bytes_removed=0i store_append_accounts=45i store_find_store=0i store_hash_accounts=0i build_meta_time=46i read_only_cache=36i
datapoint: shrink_stats num_slots_shrunk=2989i storage_read_elapsed=0i index_read_elapsed=309356i find_alive_elapsed=10085i create_and_insert_store_elapsed=56001i store_accounts_elapsed=353106i update_index_elapsed=180224i handle_reclaims_elapsed=88388i write_storage_elapsed=0i rewrite_elapsed=696774i drop_storage_entries_elapsed=84i recycle_stores_write_time=360i accounts_removed=4164i bytes_removed=2875392i store_append_accounts=161879i store_find_store=0i store_hash_accounts=0i build_meta_time=166724i read_only_cache=128213i

[codecov]

Codecov Report

Merging #17328 (50f034a) into master (6cba534) will decrease coverage by 0.0%.
The diff coverage is 90.6%.

❗ Current head 50f034a differs from pull request most recent head c58af22. Consider uploading reports for the commit c58af22 to get more accurate results

@@            Coverage Diff            @@
##           master   #17328     +/-   ##
=========================================
- Coverage    82.7%    82.7%   -0.1%     
=========================================
  Files         421      423      +2     
  Lines      118048   118054      +6     
=========================================
- Hits        97664    97645     -19     
- Misses      20384    20409     +25     

[jeffwashington]

@sakridge suggested simpler logic.

Pull request has been modified.