Fix fetchBlob in TransferManager to compute from file cache only if entry is not present

[rayshrey]

Description

Fix fetchBlob in TransferManager to compute from file cache only if entry is not present

Related Issues

Resolves #18658

Check List

• Functionality includes testing.
• API changes companion pull request created, if applicable.
• Public documentation issue/PR created, if applicable.

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[github-actions]

✅ Gradle check result for bf175e7: SUCCESS

[codecov]

Codecov Report

Attention: Patch coverage is 75.00000% with 1 line in your changes missing coverage. Please review.

Project coverage is 72.83%. Comparing base (0874e58) to head (bf175e7).
Report is 10 commits behind head on main.

Files with missing lines	Patch %	Lines
...arch/index/store/remote/utils/TransferManager.java	75.00%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##               main   #18661      +/-   ##
============================================
+ Coverage     72.80%   72.83%   +0.03%     
+ Complexity    68437    68433       -4     
============================================
  Files          5563     5563              
  Lines        314174   314172       -2     
  Branches      45554    45555       +1     
============================================
+ Hits         228726   228825      +99     
+ Misses        66871    66817      -54     
+ Partials      18577    18530      -47     

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[github-actions]

❌ Gradle check result for c4f8e86: FAILURE

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❌ Gradle check result for 3bc468c: FAILURE

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❌ Gradle check result for be3dccc:

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[github-actions]

❌ Gradle check result for e280fe6: FAILURE

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