Fix mapping char_filter when mapping a hashtag (#7591)

[nathanmyles]

Signed-off-by: Nathan Myles myles.n.a@gmail.com

Issue: #7308 (cherry picked from commit e049338)

[nathanmyles]

Backports: #7591

[github-actions]

Gradle Check (Jenkins) Run Completed with:

• RESULT: ❌
• URL: https://build.ci.opensearch.org/job/gradle-check/17927/
• CommitID: a425216
  Please examine the workflow log, locate, and copy-paste the failure(s) below, then iterate to green.
  Is the failure a flaky test unrelated to your change?

[kartg]

Tests with failures:
 - org.opensearch.remotestore.SegmentReplicationUsingRemoteStoreIT.testPressureServiceStats
 - org.opensearch.remotestore.SegmentReplicationUsingRemoteStoreIT.testDropPrimaryDuringReplication

Flaky test failures #7592 and #8059

WIll refire Gradle check

[github-actions]

Gradle Check (Jenkins) Run Completed with:

• RESULT: UNSTABLE ❕
• TEST FAILURES:

      2 org.opensearch.remotestore.SegmentReplicationUsingRemoteStoreIT.testPressureServiceStats
      1 org.opensearch.remotestore.SegmentReplicationUsingRemoteStoreIT.testDropPrimaryDuringReplication
      1 org.opensearch.remotestore.RemoteStoreRefreshListenerIT.testRemoteRefreshRetryOnFailure

• URL: https://build.ci.opensearch.org/job/gradle-check/17939/
• CommitID: a425216
  Please review all flaky tests that succeeded after retry and create an issue if one does not already exist to track the flaky failure.

[codecov]

Codecov Report

Merging #8146 (a425216) into 2.x (4a090af) will decrease coverage by 0.05%.
The diff coverage is 61.53%.

@@             Coverage Diff              @@
##                2.x    #8146      +/-   ##
============================================
- Coverage     70.71%   70.67%   -0.05%     
- Complexity    56848    56872      +24     
============================================
  Files          4703     4703              
  Lines        269056   269100      +44     
  Branches      39770    39772       +2     
============================================
- Hits         190263   190174      -89     
- Misses        62452    62596     +144     
+ Partials      16341    16330      -11     

Impacted Files	Coverage Δ
...search/index/translog/InternalTranslogManager.java	64.78% <0.00%> (+5.50%)	⬆️
...opensearch/index/translog/NoOpTranslogManager.java	64.51% <0.00%> (-2.16%)	⬇️
...rg/opensearch/index/translog/RemoteFsTranslog.java	72.83% <0.00%> (-2.17%)	⬇️
...n/java/org/opensearch/index/translog/Translog.java	80.76% <0.00%> (+0.57%)	⬆️
...dex/translog/transfer/TranslogTransferManager.java	79.77% <33.33%> (-2.69%)	⬇️
...in/java/org/opensearch/index/shard/IndexShard.java	70.43% <54.54%> (+0.17%)	⬆️
...c/main/java/org/opensearch/index/IndexService.java	74.66% <75.00%> (-0.96%)	⬇️
...earch/index/store/RemoteSegmentStoreDirectory.java	90.69% <80.00%> (-0.81%)	⬇️
...n/java/org/opensearch/search/query/QueryPhase.java	78.80% <88.88%> (ø)
...arch/analysis/common/MappingCharFilterFactory.java	50.00% <100.00%> (ø)
... and 3 more

... and 459 files with indirect coverage changes