Support FIPS build w/ CPU Jitter

[justsmth]

Issues:

Addresses: CryptoAlg-2814

Description of changes:

• Detects environment variable AWS_LC_FIPS_SYS_CPU_JITTER_ENTROPY indicating that AWS-LC should be built to use cpu jitter entropy.
• Adds functions to allow consumers to verify cpu jitter entropy is in use at runtime.

Call-outs:

• The required FIPS_is_entropy_cpu_jitter function is not yet available on the FIPS branch. So the check currently only verifies that the "cpu_jitter_entropy" configuration was successfully detected by the build scripts.
• This PR depends on: Pregen bindings for aarch64-linux-android; Prepare aws-lc-sys v0.25.0 #649

Testing:

• Added script/CI that verifies that the fips_cpu_jitter_entropy() assertion succeeds.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license and the ISC license.

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 73.07692% with 7 lines in your changes missing coverage. Please review.

Project coverage is 92.84%. Comparing base (c358484) to head (9c48333).
Report is 150 commits behind head on main.

Files with missing lines	Patch %	Lines
aws-lc-rs/src/lib.rs	73.07%	5 Missing and 2 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #657      +/-   ##
==========================================
- Coverage   95.80%   92.84%   -2.96%     
==========================================
  Files          61       68       +7     
  Lines        8143     9743    +1600     
  Branches        0     9743    +9743     
==========================================
+ Hits         7801     9046    +1245     
- Misses        342      407      +65     
- Partials        0      290     +290     

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