Backport nmslib 2.0.11 upgrade to 1.12

[jmazanec15]

Issue #, if available:
#302

Description of changes:
Backport update to nmslib upgrade to 2.0.11 to support ARM in older versions.

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[codecov]

Codecov Report

Merging #305 (d6d1716) into opendistro-1.12 (fbf9566) will not change coverage.
The diff coverage is 100.00%.

@@                Coverage Diff                 @@
##             opendistro-1.12     #305   +/-   ##
==================================================
  Coverage              79.49%   79.49%           
  Complexity               359      359           
==================================================
  Files                     58       58           
  Lines                   1414     1414           
  Branches                 129      129           
==================================================
  Hits                    1124     1124           
  Misses                   242      242           
  Partials                  48       48           

Impacted Files	Coverage Δ	Complexity Δ
...istroforelasticsearch/knn/index/KNNIndexCache.java	92.30% <ø> (ø)	35.00 <0.00> (ø)
...istroforelasticsearch/knn/index/KNNIndexShard.java	92.00% <ø> (ø)	10.00 <0.00> (ø)
...pendistroforelasticsearch/knn/index/KNNWeight.java	97.14% <ø> (ø)	10.00 <0.00> (ø)
...index/codec/KNN80Codec/KNN80DocValuesConsumer.java	70.88% <ø> (ø)	15.00 <0.00> (ø)
...forelasticsearch/knn/index/util/NmsLibVersion.java	100.00% <100.00%> (ø)	2.00 <0.00> (ø)
...stroforelasticsearch/knn/index/v2011/KNNIndex.java	76.74% <100.00%> (ø)	8.00 <1.00> (?)

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[vamshin]

LGTM!