Building DJL For aarch64

[hd1080p]

Description

This PR adds support for compiling/building Pytorch JNI for aarch64 ARM architecture.

Changelist

• Adding aarch64 cross-compiler dependencies to build-pytorch-jni-linux in github action
• Get Python 3.6 to make python3 get-pip.py to get the github action to work (open to just making the script compatible with the latest version)
• Moved files.each in prepareNativeLib(...) to a separate function
• Download the necessary dependencies and copy native lib if aarch64 specific
• Updated Pytorch version to 1.10.2

Testing

• Ran CXX=aarch64-linux-gnu-gcc ./gradlew compileJNI -Paarch64 -Ppt_version=$PYTORCH_VERSION locally to verify build succeeded.
• Ran github actions in private repository and succeeded up to the AWS Credentials step (at this point it's been built successfully)

[codecov-commenter]

Codecov Report

Merging #1526 (49026fc) into master (bb5073f) will decrease coverage by 1.36%.
The diff coverage is 50.03%.

@@             Coverage Diff              @@
##             master    #1526      +/-   ##
============================================
- Coverage     72.08%   70.72%   -1.37%     
- Complexity     5126     5352     +226     
============================================
  Files           473      500      +27     
  Lines         21970    23370    +1400     
  Branches       2351     2552     +201     
============================================
+ Hits          15838    16528     +690     
- Misses         4925     5558     +633     
- Partials       1207     1284      +77     

Impacted Files	Coverage Δ
api/src/main/java/ai/djl/modality/cv/Image.java	69.23% <ø> (-4.11%)	⬇️
...i/djl/modality/cv/translator/BigGANTranslator.java	21.42% <ø> (-5.24%)	⬇️
...odality/cv/translator/BigGANTranslatorFactory.java	33.33% <0.00%> (+8.33%)	⬆️
...nslator/InstanceSegmentationTranslatorFactory.java	14.28% <0.00%> (-3.90%)	⬇️
.../modality/cv/translator/YoloTranslatorFactory.java	8.33% <0.00%> (-1.67%)	⬇️
...i/djl/modality/cv/translator/YoloV5Translator.java	5.69% <0.00%> (ø)
...odality/cv/translator/YoloV5TranslatorFactory.java	8.33% <0.00%> (-1.67%)	⬇️
...pi/src/main/java/ai/djl/ndarray/BytesSupplier.java	54.54% <0.00%> (-12.13%)	⬇️
...pi/src/main/java/ai/djl/repository/Repository.java	83.33% <ø> (ø)
...l/training/loss/SigmoidBinaryCrossEntropyLoss.java	64.00% <0.00%> (ø)
... and 198 more

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