[Azure Search] Add missing ConfigureAwait(false) to .NET SDK rewrite rule

[brjohnstmsft]

Related: Azure/azure-sdk-for-net#6254

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[AutorestCI]

Automation for azure-sdk-for-python

Nothing to generate for azure-sdk-for-python

[AutorestCI]

Automation for azure-sdk-for-ruby

Encountered a Subprocess error: (azure-sdk-for-ruby)

Command: ['/usr/local/bin/autorest', '/tmp/tmpi7u9hzs1/rest/specification/search/data-plane/Microsoft.Azure.Search.Data/readme.md', '--perform-load=false', '--swagger-to-sdk', '--output-artifact=configuration.json', '--input-file=foo', '--output-folder=/tmp/tmp1morn_79']
Finished with return code 7
and output:

AutoRest code generation utility [version: 2.0.4283; node: v8.12.0]
(C) 2018 Microsoft Corporation.
https://aka.ms/autorest
Failure:
Error: Unable to start AutoRest Core from /root/.autorest/@microsoft.azure_autorest-core@2.0.4370/node_modules/@microsoft.azure/autorest-core
Error: Unable to start AutoRest Core from /root/.autorest/@microsoft.azure_autorest-core@2.0.4370/node_modules/@microsoft.azure/autorest-core
    at main (/opt/node_modules/autorest/dist/app.js:232:19)
    at <anonymous>

/root/.autorest/@microsoft.azure_autorest-core@2.0.4370/node_modules/@microsoft.azure/autorest-core/dist/app.js:33
    autorest_core_1.Shutdown();
    ^
ReferenceError: autorest_core_1 is not defined
    at process.on (/root/.autorest/@microsoft.azure_autorest-core@2.0.4370/node_modules/@microsoft.azure/autorest-core/dist/app.js:33:5)
    at emitOne (events.js:121:20)
    at process.emit (events.js:211:7)
    at process.emit (/node_modules/source-map-support/source-map-support.js:439:21)
fs.js:612
  return binding.close(fd);
                 ^

Error: EBADF: bad file descriptor, close
    at Object.fs.closeSync (fs.js:612:18)
    at StaticVolumeFile.shutdown (/opt/node_modules/autorest/dist/static-loader.js:352:10)
    at StaticFilesystem.shutdown (/opt/node_modules/autorest/dist/static-loader.js:406:17)
    at process.exit.n [as exit] (/opt/node_modules/autorest/dist/static-loader.js:169:11)
    at printErrorAndExit (/node_modules/source-map-support/source-map-support.js:423:11)
    at process.emit (/node_modules/source-map-support/source-map-support.js:435:16)
    at process._fatalException (bootstrap_node.js:391:26)

[AutorestCI]

Automation for azure-sdk-for-go

Nothing to generate for azure-sdk-for-go

[AutorestCI]

Automation for azure-sdk-for-js

Nothing to generate for azure-sdk-for-js

[azuresdkci]

Can one of the admins verify this patch?

[AutorestCI]

Automation for azure-sdk-for-java

Nothing to generate for azure-sdk-for-java

[sarangan12]

This seems to be specific to .NET SDK. Assignng it to @dsgouda for review

[dsgouda]

LGTM